What is EXIF data?

Published 19 August 2026

EXIF (Exchangeable Image File Format) is a block of structured data that cameras and phones write directly into a photo file alongside the pixels — camera settings, a timestamp, often GPS coordinates, and a second, smaller copy of the image most people never know is there. It isn't a separate file. It's embedded inside the photo itself, defined by a standard every camera and phone manufacturer implements against.

What EXIF actually is, structurally

EXIF is defined by CIPA DC-X008, maintained by the Camera & Imaging Products Association — the same standards body behind the format every major camera and phone manufacturer targets. The genuinely useful thing to know is what EXIF is built from: it's a complete miniature TIFF file, using TIFF's own tag structure, embedded inside a JPEG's APP1 marker segment (or, for a TIFF photo, folded directly into the file's own tag directory). If you've ever wondered why EXIF and TIFF metadata look so similar, that's why — one is built from the other's format, not just inspired by it.

The five sub-directories, and what's in each

A TIFF-style structure is organized into Image File Directories (IFDs), and a full EXIF block can carry up to five of them, each holding a different category of information:

• IFD0 — the base image directory: make, model, orientation, resolution, and pointers to the sub-directories below.
• Exif sub-IFD — camera settings at capture: exposure time, aperture, ISO, focal length, the exact timestamp, and often the camera body and lens serial numbers.
• GPS sub-IFD — latitude, longitude, and frequently altitude, typically accurate to within a few metres.
• Interop IFD — interoperability data for compatible printers and viewers; rarely populated, rarely relevant to privacy.
• IFD1 — a second, smaller copy of the image: an embedded thumbnail.

The thumbnail nobody thinks about

IFD1 is the part almost nobody expects. Cameras generate a low-resolution preview image at the moment of capture and store it inside the EXIF block itself, so software can show a fast preview without decoding the full-size photo. That thumbnail is generated once, at capture — which means if you later crop out a background detail, blur a face, or censor part of the full-size image, the original, uncropped, unedited version can still be sitting inside the file as that hidden thumbnail, entirely unaffected by whatever you did to the visible image. A tool that only shows you the main picture and never surfaces IFD1 is showing you half the file.

Which formats actually carry EXIF

JPEG carries it in an APP1 marker segment — the most common home for EXIF, since it's the default output of nearly every camera and phone. TIFF carries the equivalent data natively in its own tag directory, since EXIF's structure is a TIFF file to begin with. Since the W3C's PNG Specification (Third Edition), PNG can carry a complete EXIF block in a dedicated eXIf chunk, and macOS in particular writes one into every PNG it creates from a screenshot or conversion. WebP carries EXIF in its own RIFF container chunk. GIF and BMP predate — or in BMP's case, simply never adopted — any EXIF mechanism at all, which is why those two formats carry close to none of it.

EXIF, IPTC and XMP aren't the same thing

A single photo can carry three separate, overlapping metadata systems at once, and confusing them is the most common reason a "cleaned" photo isn't actually clean. EXIF is camera-authored technical data, structured as TIFF tags — see how JPEG actually stores it for the marker-by-marker breakdown. IPTC is older still — a newswire captioning and credit standard from the 1990s, now most often embedded via a Photoshop resource block rather than written by cameras. XMP is Adobe's newer mechanism: an RDF/XML packet, syntactically nothing like EXIF's binary tags, that frequently duplicates the same author, copyright and timestamp fields under entirely different key names. A tool that reads only the EXIF block and calls the job done can leave your name sitting in the XMP packet a few hundred bytes away, written in a format the first tool never learned to parse.

Why it exists

None of this was designed with surveillance in mind. EXIF exists so a photo printer knows which way is up, so editing software can show correct exposure settings, and so a camera roll can be sorted by capture time without reading a filename. The privacy problem isn't the standard — it's that the same fields useful for interoperability are also, incidentally, a precise record of where you were and what equipment you were carrying, and most people have no idea it's riding along in every photo they share.

See it in your own photo

The fastest way to understand EXIF is to look at a real one. Drop a photo into the JPG or TIFF tool and you'll see every field this page describes, ranked by what it actually reveals about you, before anything is removed. Curious whether removing it costs you anything? It doesn't — the pixels and the metadata live in separate parts of the file.