Photo file formats, checking files, and moving to new drives

What HEIC, JPEG, PNG, TIFF and raw files are, why the originals stay as they came, how to check once a year that the files still open, and when to move to a new drive.

The formats in a family library Understand

A file format is the way a file's contents are written down, so that a program knows how to read it back. The file extension, the letters after the last period in a file name (IMG_4021.HEIC, IMG_4021.JPG), usually tells you the format. Look at the names in a folder you exported or on the computer. Where a phone or computer hides extensions, its file information shows the kind of file; the place to look differs by device, so check your own.

Formats differ in one way that matters most here. A lossy format makes a file smaller by throwing away detail the eye is unlikely to miss, and every time the picture is saved again, more goes. A lossless format makes a file smaller, or not, without losing anything. Principle

The rows come from the Library of Congress's format descriptions: HEIC, PNG (all of its compression is lossless), TIFF, camera raw, DNG and ProRAW, which is built on DNG. The formats table adds each archive's rating and the sources. Write the formats you found on the plan sheet's "formats in the library" line, for example "HEIC, JPEG, MOV; TIFF scans".

What the archives say, in short: the Library of Congress's Recommended Formats Statement for 2025 to 2026 prefers TIFF, JPEG 2000, PNG and JPEG for photographs, accepts DNG and camera raw, and does not list HEIC (LoC's Recommended Formats, still images). It is written for published material the Library acquires, not as advice to families. The National Archives' preservation plans rate HEIC moderate risk and say that if a HEIC file can be easily rendered, it is recommended to leave it as it is (NARA's Digital Preservation Framework). Neither tells a family to convert its photos. The side-by-side table is under Go deeper.

HEIC: leave it as it is

HEIC is the High Efficiency Image format with HEVC compression. Apple made it the iPhone's default with iOS 11 in 2017, according to the Library of Congress. Apple says HEIF and HEVC compress better than JPEG and H.264 while keeping the same visual quality, which is Apple's claim (Apple's Using HEIF or HEVC media). Phone videos follow the same setting: HEVC on High Efficiency, H.264 on Most Compatible.

This manual's default: keep every HEIC original as it came, make JPEG copies only for sharing, and change the iPhone's camera setting only if a device in your household cannot open HEIC. Convention The reasons are the National Archives' advice to leave a HEIC that opens easily, and the fact that converting one lossy file into another lossy format (HEIC to JPEG) compresses the picture a second time.

The iPhone setting, as Apple describes it: Settings > Camera > Formats. High Efficiency takes HEIC photos and HEVC video; Most Compatible takes JPEG and H.264. Apple says the setting applies to new photos and videos only, so changing it converts nothing taken before. Product-specific

Where HEIC turns into JPEG on its own

• Sharing. Apple says that photos sent by AirDrop, Messages or email to a device that does not support HEIC might be converted to JPEG. In iOS 27 the Share sheet's Options offer Automatic, Current (no conversion) and Most Compatible, which may convert to JPEG (Apple's Share photos and videos on iPhone). Sharing through iCloud Photos keeps the original format. Sharing photos covers quality when you send.
• Copying by cable to a computer. Apple says photos imported by USB into Photos, Image Capture or a PC might be converted to JPEG, and gives a setting to stop it: Settings > Apps > Photos, then Keep Originals near the bottom. On an older iOS version the menu may differ; check your own iPhone.

Can every device in the house open HEIC?

Test it: copy one HEIC photo to each computer and tablet in the household and open it. Test it The Library of Congress's HEIC entry, last updated in 2021, said Windows 10 then needed separately installed codecs; we found no current Microsoft page, so the test is the evidence. If one household device cannot open HEIC, there are two choices, in this order: give that device JPEG copies when it needs them, or switch the iPhone to Most Compatible for new photos. Either way, the HEIC originals stay.

JPEG: keep the original, edit a copy

JPEG is the most widely readable photo format, and it is lossy. What wears a JPEG down is narrower than many people think. The Library of Congress's blog explains that opening a JPEG changes nothing; the loss comes when you modify a JPEG and save it, which compresses it again, and after several rounds of editing and saving the damage starts to show (The Signal, What People Are Asking About Personal Digital Archiving). Principle

So the rule, as the post puts it, is to leave the original alone and make edits on a copy saved under a new name. Convention Apple says iCloud Photos stores your originals so you can revert an edit; a file you edit and save in another program on a computer may have no such net. Converting a JPEG to TIFF stops later loss on that copy and restores nothing that was lost before.

Raw files

Camera raw files hold what the camera's sensor recorded before the camera turned it into a JPEG. Each camera maker has its own raw formats. The Library of Congress says all raw formats need special software to turn them into usable pictures, and that because the formats are proprietary and undocumented there is a risk a given one will not be supported in the long term, especially if its maker goes out of business. Product-specific It still accepts camera raw in its recommended formats. DNG (Digital Negative) is Adobe's openly documented raw format; Apple's ProRAW is built on it.

This manual's default for a camera that saves raw and JPEG pairs: keep both, in the same folder, with the names the camera gave them, so IMG_2041.NEF and IMG_2041.JPG stay together. Convention The JPEG is the picture anyone can open; the raw file is what you go back to for a better print. Folders and file names explains why renaming can split a pair. Include one raw file in each yearly check, opened in the software you use now. The National Archives' plan to turn some raw formats into DNG is under Go deeper.

Checking that the files still open

A file can stop opening without anyone touching it: a drive develops a bad spot, a copy is cut off halfway, a program that read an old format is gone. Some of this is silent. The Library of Congress says to check your photos at least once a year to make sure you can read them (Library of Congress, Keeping Personal Digital Photographs). That is the yearly check, and its simplest form is opening a sample.

This manual's sample: ten photos from your oldest copy, spread across the years, with at least one video and, if you have them, one raw file and one scan. Convention Open each at full size. If one will not open, open the same file from another copy; if that one opens, replace the bad file from the good copy and check more files from the bad one. Write the date and the result on the test sheet of the backup page. The test in Backups opens one photo from every copy; this check goes deeper into the oldest.

Checksums, in one paragraph

A checksum is a short string of letters and digits calculated from a file's contents. The Digital Preservation Coalition calls it a digital fingerprint: the smallest change to the file changes the checksum completely (DPC's Fixity and checksums). Fixity is the DPC's word for the assurance that a file has not changed. A Library of Congress post shows two pictures that look identical, two bits apart, with completely different checksums (The Signal, Protect Your Data: File Fixity). Opening a photo catches a file that is broken; a checksum also catches a file that changed without looking different. One cause is bit rot, the slow decay of stored data. A household can do without checksums; the steps for making and comparing them with a computer's own tools are under Go deeper.

Drives, discs, cards and cloud accounts

The Library of Congress puts it plainly: all digital storage media have a short life. It names three things that shorten it: how durable the medium is, how it is used, stored and handled, and obsolescence, when computers no longer have the drive, connector or software to read it (LoC's How Long Will Digital Storage Media Last?). Principle That paper gives no years for any medium. The figures that do exist each measure something narrow.

So this manual does not pick a medium by its lifespan. Whatever holds your copies, the protection is the same: more than one copy, a yearly check, and a move to new media on a schedule. Discs from the 2000s, like the CD-Rs many families have, are a reason to copy the photos off while they still read. Getting photos out covers reading them.

Cloud accounts last while they are used and paid. Google says photos might be deleted if you do not use Google Photos for two years or more, or if you are over your storage limit for two years, and that it emails at least three months before (Google's Photos activity and storage page). Amazon deletes files from an account with no activity for two years, after notice (Amazon's File Retention Policy). Microsoft says it might delete a OneDrive that has been over its limit for six months (Microsoft's storage quotas page). Product-specific Signing in to every photo account once a year is on the routine; services compared lists each rule with its date.

The yearly check, and moving to a new drive

The Library of Congress gives two intervals for personal photos: check your photos at least once a year, and create new media copies every five years or when necessary to avoid data loss. This manual uses both. Convention Each drive gets a move-by year: the year it was bought plus five, or sooner at the first sign of trouble. Write both years on the copies sheet of the backup page. If you do not know when a drive was bought, our suggestion is to treat its move-by as the next yearly check. Preference

Signs of trouble, by this manual's list: the drive is not recognized, or only sometimes; copying to or from it fails or slows to a crawl; a file that opened before will not open now; the drive has been dropped or got wet. Convention Any one of them means copy everything to a new drive from a good copy, then test the new drive.

Put the date in your calendar and tick the lines on the routine sheet, which carries these items under "Each year" and "Every five years". Routines and handing on builds the whole yearly routine around them. The Digital Preservation Coalition gives shorter intervals for some media; they are under Go deeper.

Prints: for looking at, not for keeping the files

A printed set of the photos that matter most is a fine way to see them and to share them with people who do not look at screens. This manual does not count it as a copy of the library or as the preservation copy. Convention The Northeast Document Conservation Center says color prints made from digital files "are not considered preservation quality" (NEDCC's Creating Long-Lasting Inkjet Prints). The Image Permanence Institute's storage table rates both traditional color photographs and inkjet prints as likely to suffer significant damage at room temperature, and it recommends cold storage for inkjet prints (IPI's Guide to Preservation of Digitally-Printed Images). A print also keeps no file name, date or caption you do not write on it.

If you print, NEDCC says pigment inks are more stable than dye inks, and that office paper contains ingredients that eventually destroy the image. Store prints in photo-safe enclosures in a cool, dry room, as Prints, slides and negatives describes, and keep the files and their copies as the record. One library that disagrees is under Go deeper.

See it: Nadia, Leo and Ruth See it

Pages to read alongside, each free:

• Apple, Using HEIF or HEVC media on Apple devices: the Formats setting, and where HEIC turns into JPEG.
• Library of Congress, The Signal (2013): JPEG, TIFF and when a JPEG loses quality.
• Digital Preservation Coalition, Fixity and checksums: the plainest explanation of checksums we found.

Practice: the first yearly check Practice

Minimum: write the formats on the plan sheet and each drive's year on the backup sheet, and open ten photos from the oldest copy. Time: about 45 minutes. Materials: your oldest copy (usually a drive), the phone or computer you use now, the plan sheet, the backup sheet, the routine sheet and your calendar.

1. Open one year's folder and read the extensions. Note every kind you see. Do the same for scans, if you have them.
2. Write the formats on the plan sheet.
3. Write each drive's purchase year and move-by year on the backup sheet; "unknown" if you do not know, with the next yearly check as move-by.
4. Open ten photos from the oldest copy, spread across the years, plus one video, and one raw file and one scan if you have them. Write the date and the result.
5. If anything fails to open, open the same file from another copy, and replace the bad one from the good one.
6. Put the next yearly check in your calendar and tick "Open a sample from every copy" on the routine sheet.

Your photos Your photos

Check your work Check your work

Criteria

• Does the plan sheet name every format in the library, scans and video included?
• Are the originals unchanged, with edits and JPEG copies in separate files?
• Does every drive on the backup sheet have a purchase year (or "unknown") and a move-by year?
• Did ten photos, a video and any raw files open from the oldest copy, with the date written?
• Is the next yearly check in the calendar and on the routine sheet?

Worked example

Nadia's plan sheet says "HEIC, JPEG, PNG, MOV". Her backup sheet shows both drives bought this year, move-by five years on. Her test sheet records ten photos and one video opened from the home drive, all fine, with the date. Her calendar has the same date next year. It passes. It does not say the drives will last five years; the move-by is a date to act, and the copy at Lila's covers a drive that fails first.

Common mistakes

• Converting the whole library to JPEG "to be safe". It compresses every photo again and gains nothing the archives ask for.
• Editing and saving over a JPEG original. Save the edit as a new file.
• Renaming raw and JPEG pairs separately. The pair loses its link.
• Reading a disc's or drive's life off a package. The figures are test estimates; the yearly check is the evidence.
• Counting a printed album as a backup. It is a way to look, not a copy of the files.
• Testing only the newest copy. The oldest copy is where trouble shows first.

What is still unresolved

Which formats will open in twenty years is not knowable now; the five-yearly check that every format still opens is how you find out in time. Whether you keep up the yearly check is the routine in Routines and handing on. How photos travel when you send them is in Sharing photos, and scan formats are in Prints, slides and negatives.

Knowledge check and scenario

Checklist

• The formats are on the plan sheet, each drive's year is on the backup sheet, and ten photos opened from the oldest copy.
• The originals stay as they came; edits and JPEG copies are separate files.
• The yearly check is in my calendar and on the routine sheet.
• I compared checksums for ten files across two copies. (Go deeper; optional)