Reference
What EXIF data actually is
EXIF is the block of structured data your camera writes inside every photo. Most of it you will never need. A handful of fields do real work — here is what each one means.
Where EXIF came from
EXIF stands for Exchangeable Image File Format. It was standardised in 1995 so that digital cameras could record shooting conditions in a way any program could read back. The standard has been extended repeatedly since, which is why it contains fields for things no phone has ever measured.
The practical consequence: EXIF is a large, sparse container. A photo has slots for hundreds of values and fills a few dozen. Empty slots are not errors.
The fields that matter
When the photo was taken
| Field | What it means |
|---|---|
| DateTimeOriginal | The moment the shutter fired. This is the one people mean by "the date". |
| DateTimeDigitized | When the image was written to storage. On a phone, effectively identical. |
| OffsetTimeOriginal | The time zone offset, e.g. −04:00. Without it, a timestamp is ambiguous. |
| SubsecTimeOriginal | Fractions of a second, for burst sequencing. |
Where the photo was taken
| Field | What it means |
|---|---|
| GPSLatitude / GPSLongitude | Coordinates, stored as degrees-minutes-seconds with a separate N/S and E/W reference. |
| GPSAltitude | Metres above or below sea level, with a reference byte for which. |
| GPSImgDirection | Compass bearing the camera was pointing. Useful for knowing which façade you photographed. |
| GPSHPositioningError | The device's own estimate of accuracy, in metres. Rarely read, quietly valuable. |
| GPSDateStamp / GPSTimeStamp | UTC time from the satellites, independent of the device clock. |
That last pair is worth knowing about. Because GPS time comes from satellites rather than the phone's clock, it provides a cross-check against a device whose time was set wrong.
What took the photo
| Field | What it means |
|---|---|
| Make / Model | Manufacturer and device, e.g. Apple / iPhone 16 Pro. |
| LensModel | Which lens on a multi-camera phone, including its focal length and aperture. |
| Software | OS or app version that wrote the file. Changes if the photo is edited. |
How it was exposed
| Field | What it means |
|---|---|
| FNumber | Aperture. Fixed on most phone lenses. |
| ExposureTime | Shutter duration in seconds, usually a fraction. |
| ISOSpeedRatings | Sensor sensitivity. Stored as a list, which is why it sometimes displays oddly. |
| FocalLength | Actual focal length in millimetres. |
| FocalLenIn35mmFilm | The 35mm-equivalent, which is the number most people can picture. |
| Flash | A bit field describing whether the flash fired and why. |
Fields people expect and will not find
- The photographer's name. Phones do not write it. It is an IPTC field, not EXIF, and has to be added deliberately.
- A place name. EXIF stores coordinates, never an address. Turning 35.646, 139.713 into a street requires a lookup against a mapping service.
- Who or what is in the photo. Face and subject recognition live in your photo library's database, not in the file.
- Any guarantee of truth. Nothing in EXIF is signed or verified. Every field is writable after the fact by ordinary tools.
How to read it without installing anything
iPhone
Open a photo in Photos and swipe up. You get capture date, a map if coordinates exist, and a camera line with lens, aperture, shutter, ISO and dimensions. That covers the fields most people need.
Mac
Preview ▸ Tools ▸ Show Inspector, then the ⓘ tab. The EXIF and GPS sub-tabs list raw values, including fields Photos does not surface.
Seeing everything at once
Metadata Engraver lists every field it finds in a photo and lets you render any of them onto the image. That second part is the useful bit — a field you can read in an inspector disappears the moment the file is shared, while a field drawn into the picture does not.
Why EXIF is fragile
Two properties make EXIF less dependable than it looks.
It is easily lost. Any process that re-encodes an image can drop the whole block. Social uploads, messaging apps and some editors all do. We covered which routes strip what in why your photos lose their location data.
It is easily changed. EXIF is a plain data structure. Free tools rewrite any field in seconds, including the date and coordinates. This matters enormously if you are treating metadata as evidence — see what a timestamped photo proves.
Neither makes EXIF useless. It makes it a convenience that records what the camera believed, which is usually right and occasionally very wrong.
Common questions
Does every photo have EXIF?
Almost every photo from a camera or phone does. Screenshots, images generated by software and files that have passed through a stripping platform may have almost none. A photo with no EXIF is not damaged; it simply has nothing recorded.
Why does my photo have no GPS?
Location Services were off for the camera when the shot was taken, or the copy you are looking at was stripped in transit. The setting is per-app, so the camera can lack permission while other apps have it.
Can EXIF be edited?
Yes, trivially, by many freely available tools. No field is signed or protected. That is worth knowing before you rely on a timestamp in any dispute.
What is the difference between EXIF, IPTC and XMP?
EXIF mainly records camera and capture details. IPTC defines photo description, creator, and rights fields. XMP is a flexible metadata model and format that can represent IPTC properties and information from other schemas. A photo may contain EXIF and XMP together; see our full guide to EXIF vs IPTC vs XMP.
Is ISO really stored as a list?
Yes. ISOSpeedRatings is defined as an array, because some cameras report several values. Software that prints it without taking the first element shows something like ISO: ( 46 ), which is a display bug rather than odd data.