Image Metadata Explained: EXIF, Dimensions, Camera Data and Privacy
By Akmal Ali · Published · Updated · 14 min read
Image metadata is information stored in an image file besides the visible pixels: the format and dimensions, and depending on the file, timestamps, camera settings, editing details and sometimes GPS coordinates. EXIF is the most common standard for camera-written metadata, but it is only one kind: all EXIF is metadata, but not all metadata is EXIF.
A photo file holds more than the picture. Alongside the pixels it can carry a description of the picture: how big it is, which device made it, when, with which settings, what software touched it afterwards and, sometimes, where it was taken. That description is the image’s metadata. It is written by several different systems, stored in several different ways, and changed or thrown away at almost every step between the camera and the screen. That explains both why it is useful and why it is unreliable.
What is image metadata?
Image metadata is information stored in an image file that describes the image rather than forming part of what you see. It comes from three sources. The file format itself records what is needed to decode the picture, such as the width, height and colour type. The device that captured it, usually a phone or camera, adds details about the capture. Software that edits, exports or manages the image can add, change or remove information of its own.
Pixels vs metadata
The pixels are the picture; the metadata is information about the picture. They live in the same file, but different things create and change them.
| Pixel data | Metadata | |
|---|---|---|
| What it is | The colour of every point in the image, compressed | Descriptions of the image and how it was made |
| Examples | A face, a sky, the text on a sign | Width and height, format, camera model, date taken, GPS position, editing software |
| Visible when the image is shown | Yes | No, only in apps that read it |
| Share of a typical phone photo | Nearly all of the file | A few kilobytes |
| Kept when an app writes a new file | Yes, re-encoded | Depends entirely on the app |
What is EXIF?
EXIF, the Exchangeable Image File Format, is a metadata standard for information recorded at capture by digital cameras and phones. It is published jointly by the Japanese camera and electronics industry bodies CIPA and JEITA as CIPA DC-008; the current version, Exif 3.1, appeared in January 2026. EXIF stores its fields as numbered tags, borrowed from the TIFF format, in groups: one for the image, one for the camera settings and an optional one for GPS.
Typical EXIF fields are the camera make and model, lens, exposure time, aperture, ISO, focal length, flash, white balance, the date and time of capture, orientation and, when location was enabled, GPS latitude, longitude and altitude. No camera fills every field, and many images carry no EXIF at all: screenshots, most graphics and most images that have been through a website or an export usually have none.
Is EXIF the same as metadata?
No. EXIF is one metadata standard; metadata is the broader category. All EXIF is metadata, but not all metadata is EXIF. A single photo can carry several kinds side by side:
| Kind | What it records | Usually written by |
|---|---|---|
| Format fields | Width, height, colour type, bit depth; in some formats a DPI value or text notes | Whatever saved the file; always present |
| EXIF | Camera, settings, capture dates, orientation, GPS, a small preview thumbnail | Cameras and phones |
| XMP | Almost anything, as structured text: dates, ratings, keywords, editing history | Editing and cataloguing software; also phones. Created by Adobe, standardised as ISO 16684-1 |
| IPTC | Caption, creator, copyright, credit, and how the image was made | News agencies, photo libraries, editing apps |
| ICC profile | How the stored colour numbers map to real colours | Cameras, phones, editors |
Where is metadata stored inside an image file?
Every format has its own container for metadata, which is why one program can read a JPG’s metadata but not a HEIC’s, and why converting between formats can lose some of it:
| Format | How metadata is stored |
|---|---|
| JPG | Numbered “application segments” before the pixel data: EXIF and XMP in APP1, the ICC profile in APP2, older IPTC records in APP13 |
| PNG | Named chunks: an eXIf chunk for EXIF (a later addition to the format), tEXt, zTXt and iTXt chunks for text, XMP inside an iTXt chunk, iCCP for the colour profile, pHYs for DPI |
| WebP | Chunks in the extended format: EXIF, XMP and ICCP |
| HEIC / HEIF | Separate items inside the file’s box structure: one for EXIF, one for XMP |
Which of these a program actually reads varies. The VektraTool Image Metadata Viewer, for example, reads EXIF, JFIF, PNG text and colour information from JPG, PNG, WebP and BMP files, reports XMP only as present, and does not read HEIC, AVIF or GIF metadata.
A real photo, layer by layer
To see how much of a file is metadata, we took apart the CC0 iPhone 14 photo that the site uses for its measured examples: a 4032 × 3024 JPG of 3,877,205 bytes. Its metadata segments add up to 15,081 bytes, 0.39% of the file.
| Segment | Size | What it holds |
|---|---|---|
| EXIF | 11,472 bytes | Camera, lens, settings, dates, a GPS position, and an 8,448-byte preview thumbnail |
| XMP | 2,795 bytes | Creation and modification dates, the editing credit, and a digital source type |
| ICC profile | 554 bytes | The colour space the phone used |
| IPTC (APP13) | 148 bytes | Date and time created, and the credit “Apple Photos Clean Up” |
| MPF index | 90 bytes | Points to a second image stored after the main one |
| JFIF | 22 bytes | A basic header, including a 300 DPI value |
Two details show why metadata is more than EXIF. First, the photo had been edited with the Clean Up tool in Apple Photos, and the XMP and IPTC records say so: the credit names the tool, and the IPTC digital source type marks the image as a composite that includes content made with “trained algorithmic media”. The EXIF block records none of this; it only gives the phone’s software version. Second, the MPF index points to a further 265,351 bytes after the main image: an HDR gain map that iPhones use to show the photo brighter on HDR screens. That is image data, not description, but it is indexed by metadata, and an app that ignores the index drops it.
Dimensions, DPI and other technical fields
Is image size metadata?
Width and height are part of the format itself: every image must record them, or it cannot be decoded. In everyday use they are counted as metadata, and viewers list them with the rest. EXIF can also record a width and height, and not every editor updates them after a crop, so when two figures disagree, trust the one the format records, which is what decoders use. The image dimensions checker reads the size from the decoded image for that reason.
What does DPI have to do with metadata?
A DPI value is a metadata field that suggests a print size. It does not change a single pixel: a 3000 × 2000 photo holds the same detail at “72 DPI” and at “300 DPI”. A file can store it in more than one place, and the iPhone photo above says 300 DPI in its JFIF header and 72 in its EXIF block. The DPI / PPI checker shows every stored value, and how to check image DPI and PPI explains what to do with them.
Why can one photo have several dates?
Because different systems record different moments. EXIF alone has three: when the shutter fired (often shown as “date taken”), when the image was digitised, which differs for a scanned print, and when the file was last changed. Since 2016 EXIF can store the time-zone offset for each, but older files and many apps leave it out, so a time can be ambiguous by several hours. The GPS block, when present, adds its own date and time in UTC. XMP can repeat the dates in another form. And separately from all of these, your computer keeps its own created and modified dates for the file, which change when the file is copied or downloaded. That is why one program can show a photo as taken last year and another as created today.
Why does the same photo appear rotated in different apps?
Camera sensors capture in one orientation. When you hold a phone upright, many phones store the pixels sideways and add an EXIF orientation value, one of eight, that tells apps how to turn the picture for display. Apps that honour the value show it upright; apps that ignore it, or tools that remove the EXIF block without turning the pixels, show it sideways. Software that writes a new file can avoid the problem by rotating the pixels themselves before saving, which is what the VektraTool image tools do.
How metadata is created, changed and lost
Metadata is not fixed when a photo is taken. Each step in a photo’s life can keep it, rewrite it or drop it, and the outcome depends on the specific app and its settings, not on the format alone.
| Stage | What commonly happens |
|---|---|
| Capture | The camera writes format fields, EXIF, often XMP and a colour profile, and GPS if location is allowed |
| Edit | The editor usually keeps the capture fields, updates the modified date and software, and may add XMP or IPTC records |
| Export or “save as” | Export settings decide what survives; many offer to remove location or all metadata |
| Convert to another format | Metadata the new format can hold may be copied, rewritten or dropped; some converters write only the pixels |
| Screenshot | A new image with its own format fields and possibly a colour profile and creation date, but none of the original photo’s capture data |
| Upload or message | Services often resize and recompress, which can remove most metadata from the copy others see; sending “as a file” usually delivers the original |
We saw the far end of that table directly. The same iPhone photo, saved again at full size by the VektraTool image resizer, kept 492 bytes of metadata: an 18-byte JFIF header and a 474-byte colour profile written by the browser. The EXIF block, GPS position, thumbnail, XMP, IPTC records and gain map were all gone. Other tools behave differently, so check rather than assume. The practical side, including a screenshot example and how to remove a location before sharing, is in how to check image metadata and what it reveals.
Can metadata reveal where, and with what, a photo was taken?
Sometimes. A photo reveals a location only if the device recorded a GPS position and nothing removed it afterwards. Phones record it only when location access is allowed for the camera, and a phone’s position outdoors is usually accurate to a few metres, enough to identify a house. A photo can identify the device through the make, model and lens fields, and some cameras record a serial number that identifies the individual camera. Editing software can add an owner or artist name. None of these fields is guaranteed to be present, and all of them can be removed or changed.
The thumbnail can show what you cropped out.
Can image metadata be edited?
Yes. Metadata is ordinary data in the file, and widely available software can change almost any field, including the capture date, the camera model and the GPS position, without touching the pixels. Fields also change without anyone intending it: an editor rewrites the modified date and software, a phone corrects its clock, an export copies some fields and drops others. Nothing in EXIF, XMP or IPTC records whether a field has been changed.
Can metadata prove a photo is authentic?
No. Metadata alone cannot prove when, where or how a photo was taken, or that it hasn’t been altered, because it can be edited, removed, copied from another file or wrong from the start. Missing metadata proves nothing either, since most shared images have lost it along the way. It is useful context that should agree with other evidence.
A newer approach, Content Credentials based on the C2PA standard, attaches a cryptographically signed record of an image’s origin and edits, so a change to the file after signing can be detected. It can still be stripped like any other metadata, and it is only present when the camera or app that made the image supports it. The VektraTool viewer does not read it.
Why image metadata matters
For privacy
A file can tell a recipient more than the picture does: a home location, the exact time, the phone model. The risk comes from sharing original files with people you don’t know: posting them on forums, sending them to buyers or strangers, or publishing them on a site that serves the original. Most images are harmless, and many have no such data at all. Checking the specific file before sharing is the proportionate response.
For photographers
Exposure time, aperture, ISO and focal length show how a picture was made, which makes metadata a record to learn from: why one shot is blurred, which lens you use most, which settings worked in low light. Cataloguing software relies on dates, ratings, keywords and captions, much of it stored as XMP, to organise large collections.
For website owners
What matters on a website is the image’s dimensions, format and file size, plus correct orientation and colour. Metadata itself is not a meaningful search ranking factor, and the bytes it adds are usually small. Removing it makes sense for privacy and to avoid publishing camera details, not as an optimisation. The exception is rights information: Google Images can show an image’s IPTC Creator, Credit Line and Copyright Notice fields, according to Google Search Central’s guide to image metadata, so keep them on images you license. Removing all metadata removes these fields too. Size images to their display width with the image resizer and check their real size with the image dimensions checker.
Does metadata affect image file size?
A little. In the iPhone photo above, all the metadata segments together were 15,081 bytes of 3,877,205, under 0.4%; more than half of that was the preview thumbnail. Pixel data and how it is compressed decide almost all of the size, so removing metadata is no substitute for compression. To make an image meaningfully smaller, use the image compressor, which re-encodes the pixels and drops the metadata along the way.
Common image metadata myths
| Myth | Reality |
|---|---|
| Converting an image always removes its metadata | It depends on the converter. Some copy metadata across, some keep only what the new format supports, some write only the pixels. |
| Social networks always strip metadata | Behaviour varies by service, upload method and over time, and the service may keep the original even when the public copy has none. |
| The date in file properties is when the photo was taken | That date belongs to the copy on your device and changes when the file is copied or downloaded. The capture date is in EXIF, if anywhere. |
| Only cameras add metadata | Editors, phones’ photo apps and cataloguing software add their own records, such as the editing credit in the example above. |
| Removing metadata makes an image much smaller | Metadata is usually a fraction of a percent of a photo. Compression and dimensions decide the size. |
| Metadata is always inside the image file | Usually it is, but some photo software keeps edits and keywords in a separate .xmp “sidecar” file next to the image, especially for RAW files. |
| A 300 DPI value means a high-quality image | DPI is a print-size suggestion. Detail depends on the pixel dimensions. |
Image metadata field reference
| Field | Stored in | What it means | How far to trust it |
|---|---|---|---|
| Width and height | Format header | The number of pixels across and down | Reliable: decoders depend on it |
| Format | The file’s first bytes | How the image is encoded: JPG, PNG, WebP… | Reliable when read from the data; the extension can lie |
| File size | Your device | Bytes the file occupies | Reliable for that copy |
| Make, model, lens | EXIF | The device as it describes itself | Context: easily changed or removed |
| Exposure time, aperture, ISO, focal length | EXIF | How the capture was set up | Usually accurate when present |
| Date taken | EXIF, XMP | When the shutter fired, by the device clock | Only as good as the clock and time zone; editable |
| GPS position | EXIF GPS block | Latitude, longitude, often altitude | Often accurate to metres outdoors; editable |
| Orientation | EXIF | How apps should turn the stored pixels | Reliable, but lost if EXIF is removed carelessly |
| Software | EXIF, XMP | The firmware or app that last wrote the file | Context only |
| DPI | JFIF, EXIF, PNG, BMP | A suggested print density | Irrelevant to on-screen quality |
| Colour profile | ICC profile | How to show the stored colours correctly | Reliable; affects how colours look |
| Caption, creator, copyright | IPTC, XMP | Descriptive and rights information | As reliable as whoever entered it |
Viewing an image’s metadata
To see what a particular file contains, open it in the Image Metadata Viewer, which reads it in your browser and lists the fields it finds. For the walkthrough, what each result means and what to do before sharing, see how to check image metadata and what it reveals.
Sources: CIPA’s standards list, for Exif (CIPA DC-008); Adobe’s XMP specifications, whose first part is standardised as ISO 16684-1; the IPTC Photo Metadata Standard; and the C2PA specifications for Content Credentials.
Frequently Asked Questions
Does every image have metadata?
Every image file records at least its format and dimensions, because it can’t be decoded without them. Optional metadata such as EXIF, XMP and GPS is often absent, especially in screenshots, graphics and images downloaded from websites.
What is IPTC metadata?
IPTC metadata is a standard from the International Press Telecommunications Council for descriptive and rights information: captions, keywords, creator, copyright and credit. Older files store it in a Photoshop-style block; newer ones usually store it as XMP.
Can metadata show that a photo was edited with AI?
Sometimes. Some apps record it, for example with an IPTC digital source type or a Content Credentials record, as the iPhone photo in this article did. Many apps record nothing, and the record can be removed, so its absence proves nothing.
What is an XMP sidecar file?
A small .xmp text file saved next to an image, with the same name, that holds metadata such as edits, ratings and keywords. Photo software uses sidecars mainly for RAW files, which it avoids rewriting. Copying the image without its sidecar leaves that metadata behind.