How to Back Up a Smartphone

A smartphone can hold years of personal information in one small device. Photos, videos, contacts, messages, documents, notes, app data, passwords, and work files may all disappear if the phone is lost, stolen, damaged, or accidentally reset. Creating a reliable backup gives you another copy of important information so a hardware failure does not automatically become a permanent data-loss problem. A good backup is therefore less about technology and more about protecting information that may be difficult or impossible to recreate.

Learning how to back up a smartphone is easier than it may initially appear. Both iPhone and Android provide built-in cloud backup systems, while additional options such as computer backups, Google Photos, iCloud Photos, external storage, and individual app backups can provide additional protection. The most suitable method depends on what type of phone you use, how much data you have, your available cloud storage, and whether you want automatic or manually controlled copies.

One important point is that synchronization and backup are not always exactly the same thing. Some information may already be continuously synced to a cloud account rather than included inside a traditional device backup. Apple, for example, explains that iCloud Backup primarily copies information that is not already being synced to iCloud, while Android backup can include selected device data and settings depending on the app and phone.

This guide explains practical smartphone backup methods for both iPhone and Android users. You will learn how to create automatic cloud backups, save photos and videos, back up to a computer, protect contacts and messages, verify that a backup actually completed, prepare before resetting or replacing a phone, and avoid common mistakes that can leave important data unprotected.

Why Backing Up Your Smartphone Is Important

Smartphones are vulnerable to several types of failure. A device can fall into water, develop a hardware fault, become damaged beyond repair, disappear during travel, or be stolen. Software problems can also require a factory reset that removes locally stored information. Without a recent backup, replacing the hardware may restore your ability to make calls but not necessarily restore the personal information that made the old phone valuable.

Backups are also important when upgrading to a new smartphone. Instead of manually rebuilding contacts, settings, apps, and other information from scratch, a cloud or device backup can help transfer much of the existing setup to the replacement phone. Apple and Google both provide restore workflows that allow compatible backed-up information to be brought onto another device during setup.

A backup can also protect against accidental deletion, although the level of protection depends on what service stores the information. If a file is simply synchronized and you delete it everywhere, synchronization alone may not provide the historical copy you expected. Backup systems, version history, deleted-item recovery, and local copies can therefore serve different purposes.

The safest approach is not waiting until the phone begins behaving strangely. Backups should operate regularly while everything is working normally. Automatic backup greatly reduces the chance that your only copy was created months before the incident, leaving recent photographs, conversations, or other important information missing.

Understand What Smartphone Backup Actually Includes

A phone backup is not necessarily an exact duplicate of every byte stored on the device. Different systems decide which information should be copied because some data may already exist in cloud services, while certain applications use their own storage and backup systems. Understanding these differences prevents surprises when you later need to restore something.

Google says Android backup can include device data and settings, although not every application can back up or restore all of its information. The exact content varies according to the Android version, device manufacturer, applications, and backup configuration.

On iPhone, iCloud Backup stores information that is not already being continuously synchronized through iCloud. Data already stored through services such as iCloud Photos or other iCloud synchronization features does not need to be duplicated inside the same device backup in the same way.

This means you should think about backup by category. Ask where your photos, contacts, messages, documents, app data, and authentication information are stored. A strong backup strategy verifies each important category instead of assuming one button automatically protects everything contained on the phone.

How to Back Up an iPhone With iCloud

iCloud Backup is one of the easiest ways to protect an iPhone because the process can run automatically without requiring a computer. On a current iPhone, open Settings, tap your name, choose iCloud, and then open iCloud Backup. Turn on the option to back up the device if it is not already enabled. Apple also provides a Back Up Now option when you want to create a manual backup immediately.

Automatic iCloud backups normally work when the necessary conditions are met. Apple states that the device should be connected to power, connected to Wi-Fi, and have its screen locked for automatic backup. Ensuring those conditions occur regularly, such as overnight, can make the backup process largely invisible during normal use.

The backup requires enough available iCloud storage. If storage is full, the iPhone may not be able to complete another backup until you remove unnecessary stored information or increase your available storage. Do not ignore storage warnings indefinitely because they may mean your most recent backup is older than you expect.

After enabling backup, check the date of the latest successful backup occasionally. A backup setting that appears turned on is not the same as confirming the process actually completed. Network interruptions, insufficient cloud space, or account problems can all prevent an expected backup from finishing.

How to Make a Manual iPhone Backup

A manual backup is useful before installing a major software update, sending the phone for repair, replacing it, or performing a factory reset. Even when automatic backups are enabled, creating a fresh backup before a major change helps ensure that recently created information has had an opportunity to be saved.

To create an iCloud backup manually, open Settings > [your name] > iCloud > iCloud Backup and choose Back Up Now. Keep the phone appropriately connected while the backup completes. Apple provides the most recent backup information in the same area so users can verify when the device was last protected.

The amount of time required depends on the amount of data, network speed, and how much information has changed since earlier backups. The first backup can take considerably longer than later incremental backups because more information may need to be uploaded.

Avoid erasing or trading in your existing iPhone immediately after simply pressing the backup button. Wait until the process finishes and confirm that a recent backup is visible. Verification is especially important when the old phone contains information you cannot easily recreate.

How to Back Up an iPhone to a Mac

A computer backup provides another option for users who want a local copy of their iPhone information. On current versions of macOS, connect the iPhone to the Mac with an appropriate cable and select the iPhone from the Finder sidebar. Apple says Finder is used for device backups on macOS Catalina 10.15 and newer, while older systems historically used iTunes.

After selecting the device in Finder, open the relevant backup options and choose to back up the data from the iPhone to the Mac. Local backups can be useful if you prefer not to depend entirely on internet connectivity or available cloud storage.

Consider encrypting the computer backup when the option is available and appropriate. Encrypted backups can protect additional sensitive information, but the password becomes extremely important. If you create an encrypted backup and lose the password required to access it, recovering the backup may become difficult or impossible.

Remember that the computer itself also needs protection. A phone backup stored only on a laptop does not help if the laptop and phone are stolen together or the computer drive fails. A stronger approach can involve backing up the computer as well so the local iPhone backup is not stored in only one physical location.

How to Back Up an iPhone to a Windows PC

Windows users can also create local iPhone backups. Apple currently directs users to the Apple Devices app on supported Windows PCs, while iTunes may still be used in certain older configurations. Connect the iPhone using a suitable cable, open the relevant Apple software, and select the device.

If the phone asks whether you trust the computer, confirm the request only when you recognize and control that computer. You may also need to enter the iPhone passcode. This security step prevents unknown computers from freely accessing device information.

From the device management screen, choose the available backup option and allow the process to complete before disconnecting the phone. Local computer backups can be especially useful before repairs or operating-system changes because you maintain a copy directly under your own control.

Keep the PC account and storage secured. Anyone who can freely access an unprotected local backup may potentially access sensitive personal information. Encryption, a strong computer login, drive security, and appropriate backup-password management should be considered part of the phone backup strategy.

How to Back Up an Android Phone

Android includes built-in backup capabilities connected with your Google Account. On current Android guidance, Google directs users to open the Settings app, choose Google, select All services, and locate Backup under the backup and restore section. Menu names can vary slightly according to device manufacturer and Android version.

From the backup settings, verify which Google Account is being used. This is particularly important if you have several personal, work, or school accounts on the same device. A successful backup stored under an account you later forget about can be difficult to locate during device replacement.

Google also provides a Back up now option for manually creating an updated backup. This is useful before resetting the phone, changing devices, or making another major change.

Not every Android application backs up all data through the standard device backup system. Google explicitly notes that app backup behavior can vary, so applications containing critical information should be checked individually.

What Does an Android Backup Save?

Android backup is designed to preserve important device information that can help restore a phone or set up another Android device. The exact categories can vary, which is why the backup screen should be reviewed instead of assuming everything is automatically included.

Depending on the phone and applications involved, backed-up information can include device settings and supported application data. Certain Google services also handle specific categories separately, such as photos through Google Photos. Google allows users to review backup details so they can understand which information is included.

App developers still control parts of how individual app data can be saved and restored. Some applications may restore settings and history automatically, while others require their own login or separate backup process. Important specialized apps should therefore be reviewed before an old phone is erased.

Authentication applications deserve special attention. If an authenticator contains login codes for important accounts, ensure you understand the transfer or backup method supported by that authenticator before resetting or selling the phone. Losing access to the old device without account recovery options can create significant problems even if ordinary phone data was successfully backed up.

How to Back Up Photos and Videos

Photos and videos are often the most irreplaceable information on a smartphone because they contain personal memories rather than files that can simply be downloaded again. They also consume large amounts of storage, making their backup strategy especially important.

Android users can use Google Photos by opening the app, entering Photos settings, selecting Backup, and turning backup on. Google also allows users to check which account receives the photos and whether backup is currently active.

Google Photos is also available on iPhone. Users can sign in with their Google Account, open Google Photos settings, and enable Backup if they prefer Google’s photo system or want an additional cross-platform photo service.

iPhone owners can alternatively use Apple’s iCloud Photos ecosystem. Whichever service you choose, confirm that recent photographs are actually appearing in the cloud account before deleting local copies. Seeing a photo inside the phone’s gallery does not by itself prove that an online copy exists.

Back Up Your Contacts

Losing contacts can create problems that last much longer than replacing the phone itself. Numbers belonging to customers, colleagues, relatives, doctors, schools, suppliers, and other important people may have accumulated over many years.

Modern smartphones commonly synchronize contacts with an online account rather than storing them only on the physical device. On Android, contacts may be associated with a Google Account, while iPhone users may synchronize them through iCloud or another configured account.

Open the contacts or account settings and verify where new contacts are being saved. Some phones can contain a mixture of device-only, SIM-based, Google, iCloud, corporate, and other contacts. A contact stored only locally may not reappear simply because you sign into the same cloud account on another device.

Consider exporting an additional copy when contacts are especially important. A contact file stored somewhere secure can provide another recovery route if synchronization behaves unexpectedly. Avoid storing the only export on the same phone you are trying to protect.

Back Up Text Messages

Text messages may contain appointment details, addresses, family conversations, work information, and other records worth keeping. Backup behavior differs across operating systems and messaging applications, so users should confirm how their specific conversations are protected.

On Android, supported backup services can restore certain messaging information when compatible apps and devices are used. Google notes that some types of messaging data can be part of the wider backup and transfer environment, though exact support can vary by application and device configuration.

iPhone users may have messages synchronized through Apple’s cloud services depending on their iCloud settings. Because synchronization and backup are related but distinct concepts, understanding which Apple services are enabled helps clarify how conversations will return on another device.

Messaging platforms such as WhatsApp or other third-party applications may use their own backup settings. Do not assume the phone’s general backup automatically protects every message history. Open important messaging apps individually and verify their current backup status before resetting or replacing the phone.

Back Up Messaging Apps Separately When Needed

Third-party messaging applications frequently maintain their own cloud accounts, encryption systems, and backup workflows. This makes them different from ordinary applications whose data may be restored through the operating system’s general device backup.

Open each important messaging application and look for backup, transfer, export, or account settings. Verify which cloud account is being used and when the application last completed a successful backup. This is especially important if conversations contain business records or other information you need to preserve.

Encrypted messaging services may deliberately limit what can be backed up because privacy is part of their design. Some apps allow encrypted cloud backups, while others require direct device-to-device transfer or provide limited history restoration.

Do not discover these limitations after wiping the old phone. Before any device change, create a list of the communications apps you use and confirm the transfer process for each one. Several minutes of preparation can prevent losing years of conversation history.

Back Up Notes and Documents

Notes often contain more important information than users realize. Shopping lists may be replaceable, but passwords written insecurely in notes, work ideas, project details, personal writing, account numbers, and scanned documents may be difficult to reconstruct.

Determine which service stores each note. Apple’s Notes app may use iCloud or another configured account, while Android users may rely on Google Keep, manufacturer-specific note applications, Microsoft services, or other apps.

Files and documents should be reviewed in the same way. Some documents may already live inside cloud storage such as iCloud Drive, Google Drive, OneDrive, or Dropbox, while downloads and locally created files may exist only on the device.

Open the file manager and review important folders before resetting or replacing the phone. Upload locally stored documents to an appropriate cloud service or copy them to a computer. Do not assume a file is backed up simply because it appears inside a modern-looking app.

Back Up Smartphone Data to a Computer

A computer copy can provide useful protection in addition to cloud backup. Connecting the phone to a trusted computer allows you to copy photographs, videos, documents, downloads, and other accessible files to local storage.

Android phones can generally expose user-accessible storage when connected appropriately by USB, although exact transfer steps vary by manufacturer and computer operating system. This can make it straightforward to preserve folders such as photos and documents manually.

iPhone users can create structured device backups through Finder on supported Macs or the Apple Devices app on Windows. Apple specifically supports both iCloud and computer-based backup methods, allowing users to maintain an alternative backup route.

A computer backup is most valuable when that computer is also backed up. Consider keeping important local copies on an external drive or another protected storage system. Otherwise, one failed computer drive could remove your additional backup at the same time you need it.

Cloud Backup vs Local Backup

Cloud backup provides convenience because the backup is stored away from the phone and can usually be reached anywhere you can securely sign into the account. Automatic uploads also reduce the need to remember cables or manually copy files.

Cloud storage depends on an internet connection, account access, available storage, and the continued availability of the service. Large photo libraries may also require paid storage plans once free capacity is exhausted.

Local backups provide more direct control and can restore information without uploading everything across the internet. They can also be useful for people with slow connections or large data libraries. However, they require enough computer or external-drive space and need manual attention.

Using both approaches can provide stronger resilience. Cloud backup protects against losing the phone and computer in the same physical incident, while local backup gives you another copy if you temporarily cannot access the cloud account. The best strategy avoids placing every important piece of data in one location.

Use More Than One Backup for Irreplaceable Data

A single backup is much safer than having no backup, but extremely important information deserves more than one copy. Family photographs, business documents, creative projects, and other irreplaceable files should not depend entirely on one phone or one cloud account.

A simple approach is keeping the phone as the working copy, a cloud service as the automatic copy, and a computer or external drive as another copy. This creates separation between devices and services.

The copies should not all depend on the same failure point. For example, storing a phone backup on a laptop and then leaving both devices in the same bag creates vulnerability to theft. Geographic and account separation can improve resilience.

You do not necessarily need complicated enterprise backup software. The goal is simply ensuring that one accident, password problem, device failure, or service issue cannot remove every copy of the information that matters most.

Check Whether Your Backup Actually Worked

A backup that silently failed is nearly as dangerous as having no backup because it creates false confidence. After enabling automatic backup, verify periodically that the service reports a recent successful backup.

Apple provides the latest iCloud backup information inside iCloud Backup settings, while Android allows users to inspect backup details through the Google backup area.

For photos, open the cloud photo service through another device or a web interface and confirm that recent images appear. This is a stronger test than simply checking that a backup switch is enabled.

Consider whether you could actually restore the information if the phone disappeared tonight. Do you remember the account password? Do you have access to multifactor authentication? Are recovery codes available? A backup cannot help if you cannot securely access the account containing it.

Check Your Cloud Storage Space

Cloud backups can fail when the account runs out of available storage. Photos and videos are particularly likely to consume large amounts of capacity because modern phone cameras create high-resolution files.

Review storage periodically rather than waiting for an urgent warning immediately before resetting your phone. Remove unnecessary large files, old backups, or duplicates where appropriate, or increase the storage plan when your data genuinely requires more space.

Be cautious when deleting cloud data to create storage. If your photo library is synchronized, deleting a photograph from one connected device may remove it from other synchronized locations as well. Understand the service’s behavior before performing large cleanup operations.

Storage management should focus first on unnecessary information. Old device backups, duplicate videos, large downloads, and abandoned application data may provide safer cleanup opportunities than deleting irreplaceable family photos simply to save space.

Use Wi-Fi for Large Backups

Large backups can transfer many gigabytes of information, making a stable Wi-Fi connection useful. Photos and videos can require particularly large uploads when backup is being enabled for the first time.

Apple’s standard automatic iCloud backup workflow uses Wi-Fi among its normal requirements, although some iPhone configurations may allow cellular backup options.

Google Photos and other cloud applications can often be configured to control whether mobile data is used. Review these options if your mobile plan has limited data or expensive overage charges.

Leave the phone connected long enough to finish the initial upload. A backup that repeatedly begins and stops on unstable connections can take much longer than expected. Large first-time backups are often easiest when the phone can remain connected to power and reliable Wi-Fi for an extended period.

Protect Your Backup Account With a Strong Password

Cloud backup shifts the risk from losing the physical device toward protecting the account that stores the information. If somebody compromises your cloud credentials, they may potentially gain access to sensitive information even without possessing your phone.

Create a unique password for your Apple Account, Google Account, or other backup provider. Never reuse the same password across unrelated websites because a breach elsewhere could expose credentials that attackers then try against your backup account.

A password manager can make unique passwords easier to maintain. Protect the password manager itself carefully because it becomes an important part of your wider account security.

Review account recovery information periodically. An old phone number or email address you no longer control can create serious difficulties when you eventually need to restore a device. Recovery details should remain current before an emergency occurs.

Enable Multifactor Authentication

Multifactor authentication creates an additional barrier beyond the password. Even if someone steals or guesses the password, they may still be unable to enter the account without the second verification method.

This is especially valuable for cloud backup because the account may contain private photographs, documents, contacts, device information, and other sensitive data. Protecting it should be treated with the same seriousness as protecting email or financial accounts.

Keep recovery codes or backup authentication options somewhere safe when your provider offers them. Do not store the only recovery method on the phone you might lose because that can make account recovery unnecessarily difficult.

When changing phones, verify that your authentication method can be transferred correctly before wiping the old device. This is particularly important when authenticator applications or trusted-device approvals are involved.

Back Up Before Installing Major Updates

Software updates are generally important for security and reliability, but creating a recent backup before a major operating-system update provides additional protection if something unexpected happens during installation.

Most updates complete normally, so a backup should not be viewed as evidence that updating is inherently dangerous. It is simply good preparation whenever significant changes are being made to a device containing important information.

Check that the backup is recent and complete before starting the update. If storage problems prevented automatic backup for several weeks, resolve them before proceeding when possible.

This habit is especially useful on older phones or devices already experiencing hardware problems. If the phone fails during or shortly after an update for unrelated reasons, you still have another copy of important information available.

Back Up Before a Factory Reset

A factory reset removes personal information and returns the phone to a clean software state. It is sometimes used for troubleshooting, preparing a device for sale, or starting fresh after significant software problems.

Before resetting, create an updated cloud or computer backup and verify that it completed. Also check individual applications that may need separate backup or transfer procedures.

Confirm that photos, contacts, documents, and authentication methods exist somewhere outside the phone. A general device backup can be valuable, but manually reviewing critical categories provides additional confidence.

Only perform the reset after verification. Once locally stored information is erased, recovering data that was never backed up can be extremely difficult or impossible. Preparation takes far less time than attempting data recovery afterward.

Back Up Before Selling or Trading In Your Phone

Selling or trading in an old phone is one of the moments when backup mistakes become permanent. Once the device leaves your possession, you may no longer have any way to retrieve local information you forgot to transfer.

Create a fresh backup and verify critical information on another device or online service. Make sure your replacement phone can access the account and that essential photos, contacts, messages, and authentication methods have transferred correctly.

Do not erase the old phone the moment the new device powers on. Spend enough time confirming that important information is present and applications you rely on can be accessed.

After verification, follow the manufacturer’s official instructions for removing personal accounts, disabling theft-protection features where necessary, and securely erasing the device. A proper handoff protects both your data and the next owner.

Restoring an iPhone From a Backup

When setting up an iPhone, Apple provides the option to restore from an iCloud backup during the setup process. Users proceed through the setup screens until reaching the transfer options and then choose the relevant iCloud backup.

Sign into the same Apple Account associated with the backup and choose the appropriate backup according to its date and device information. The restoration process may continue in stages, with some apps and cloud content downloading after the phone becomes usable.

A stable Wi-Fi connection and power can help the process complete smoothly, particularly when restoring a large amount of information. Some content may take longer to return than the basic device settings.

After restoration, inspect critical information instead of assuming every application has returned exactly as before. Certain apps may require you to sign in again or complete their own data-recovery steps.

Restoring an Android Phone From a Backup

Android provides backup restoration during the setup of a new or reset device. Users can sign into the Google Account associated with the old phone and follow the prompts to select available backed-up data.

Google also allows users to select which apps and information should be copied during supported transfer and restore processes. The exact appearance of these screens can vary by Android version and device manufacturer.

Restoration can continue after initial setup. Google notes that some restored information can take time to finish appearing, so a phone may not look completely identical immediately after the first startup.

Review important third-party apps individually after restoration. Some services store their data primarily in their own accounts, while others may not support complete app-data restoration. Logging into each important service confirms whether further action is needed.

What to Do if Your Smartphone Is Lost or Stolen

A lost phone is exactly the situation where automatic backup becomes valuable. If your information was already stored in the cloud, you can focus on protecting the missing device instead of worrying immediately about whether your only copy of family photographs disappeared with it.

Use the official lost-device tools associated with your phone ecosystem where available. These services can help locate, lock, or remotely erase a missing device according to the platform’s capabilities and your settings.

Do not remotely erase the phone solely out of panic before understanding the consequences. If important information has not been backed up and recovery remains possible, erasing will remove local data. Security and recovery priorities need to be considered carefully.

Change critical passwords if you suspect unauthorized access and protect the cloud account containing your backup. Once a replacement device is available, you can sign into the appropriate account and restore supported information from the most recent backup.

Common Smartphone Backup Mistakes to Avoid

The first mistake is assuming automatic backup is working without ever checking it. Storage limits, sign-in problems, network issues, or app settings can prevent backups from completing while the user continues believing everything is protected.

Another mistake is treating one category of synchronization as a full device backup. Having photos in the cloud does not necessarily mean messages, settings, documents, and app data are protected. Review important data categories independently.

People also forget about app-specific data. Messaging histories, authenticator accounts, specialty note apps, financial software, games, and work applications may have separate transfer requirements that the normal phone backup does not fully cover.

Finally, many users erase their old phone too quickly. Keep access to the existing device until you have confirmed that the new phone or backup service contains everything important. Verification is the last and most important step of a safe device transition.

How Often Should You Back Up Your Smartphone?

For most people, automatic daily or regular cloud backup is far more practical than remembering to create manual copies every few weeks. The ideal frequency depends on how much new information you create and how damaging it would be to lose recent data.

Someone who takes important work photographs or receives business messages every day may need very frequent backup. Another person who uses the phone lightly might tolerate losing a few days of recent information, although automatic protection still makes sense.

Create additional manual backups before major events such as resetting the phone, installing significant updates, sending it for repair, switching platforms, or selling the device.

For especially valuable information, consider periodic local copies in addition to automatic cloud backup. Backup frequency should reflect how much data you are willing to lose, not simply how convenient the backup process feels.

Create a Simple Smartphone Backup Routine

Start by enabling the built-in automatic device backup for your operating system. Then enable photo and video backup using the cloud service you prefer. These two steps protect a large portion of the information most users care about.

Next, check contacts, messaging applications, notes, files, and authentication apps. Confirm that each important category is associated with an account or backup method you understand.

Once every few weeks or months, depending on your needs, review the date of the latest backup and confirm that recent photos or other important files appear outside the phone. This short review catches silent failures before they become disasters.

Finally, create a fresh manual backup before any major device change. This routine requires relatively little ongoing effort but significantly reduces the possibility of permanent data loss.

Final Thoughts

Learning how to back up a smartphone is one of the simplest ways to protect years of digital information. Modern iPhones and Android phones provide built-in cloud backup systems that can operate automatically, while computer and external-storage copies provide additional control and redundancy. Apple supports both iCloud and computer backups, while Google provides built-in Android backup and separate photo backup tools.

The strongest strategy is not relying blindly on one feature. Understand where your photos, contacts, messages, documents, notes, and app data are stored, because different categories may use different synchronization or backup systems.

Verification matters just as much as creating the backup. Check the latest backup date, confirm recent photographs in the cloud, protect the account with strong authentication, and ensure you know how to restore the information before an emergency happens.

Most importantly, make backup automatic wherever possible. Losing or damaging a smartphone is stressful enough without discovering that years of personal information disappeared with it. A few minutes spent configuring backup today can prevent an enormous amount of frustration later.

Frequently Asked Questions

What is the easiest way to back up a smartphone?

The easiest method is usually enabling the built-in automatic cloud backup on your phone. iPhone users can use iCloud Backup, while Android users can use Google’s device backup system.

How do I know if my phone is backed up?

Check your phone’s backup settings and look for the date and time of the most recent successful backup. Also verify important categories such as photos by checking them through the associated cloud account.

Can I back up my phone without cloud storage?

Yes. iPhone users can create local backups using Finder on a Mac or the Apple Devices app on Windows, while Android users can manually copy accessible files such as photos and documents to a computer.

Does backing up my phone save all my photos?

It depends on your configuration. Photos may be handled through separate services such as iCloud Photos or Google Photos rather than the general device backup, so confirm that photo backup is enabled independently.

Should I back up my phone before a factory reset?

Yes. Create a recent backup, confirm that it finished successfully, and verify critical photos, contacts, messages, documents, and app-specific data before erasing the phone.