Image Metadata Viewer

How to Use the Image Metadata Viewer

1. Drop or pick any image. The File API exposes name, size, type, and last-modified date without reading pixel content.
2. Review the file facts panel: MIME type as detected by the browser, byte size, last-modified timestamp, and readable name.
3. Check the dimensions panel: width and height in pixels (read by decoding the image to an ImageBitmap), derived aspect ratio, and megapixel count.
4. Scroll to the EXIF panel for JPEG inputs. The tool parses the raw ArrayBuffer to find the APP1 marker and pull out camera make, model, orientation, software used, and full datetime.
5. Inspect GPS coordinates if they are embedded. Phone cameras often record latitude and longitude in EXIF - this panel surfaces them as decimal degrees so you can see what leaks with the file.

What Is Actually Stored in an Image File

An image file is not just pixels - it is a container with a structured header, optional metadata blocks, and a compressed pixel payload. JPEG files (JFIF container, ISO/IEC 10918-1) begin with the SOI marker 0xFFD8, followed by a chain of "APP" segments: APP0 is the JFIF thumbnail, APP1 usually holds EXIF (and sometimes XMP), APP2 often carries the ICC color profile, and APP13 is Photoshop/IPTC data. The EXIF 2.32 specification defines a TIFF-style IFD (Image File Directory) inside APP1 with numbered tags: 0x010F for camera make, 0x0110 for model, 0x0132 for datetime, 0x8825 for the GPS sub-IFD containing latitude and longitude.

We parse these structures directly in the browser by reading the file into an ArrayBuffer with FileReader, then walking the byte stream to find markers and decode the tagged values. No EXIF library is downloaded at runtime - the parser is custom and minimal. PNG files use a different layout (IHDR, tEXt, zTXt, iTXt chunks per the W3C PNG specification), and WebP stores metadata in RIFF chunks (EXIF, XMP, ICCP), so the displayed data differs by format.

When Metadata Inspection Matters

• Verifying an uploaded photo is genuinely from the claimed camera and was not a screenshot of someone else\'s work (forensic check).
• Auditing your own photo library before a public post to see exactly what would leak if you forget to strip EXIF.
• Journalism: confirming the capture timestamp on a source\'s photo to corroborate timing of events.
• Real estate or architecture: reading dimensions and DPI from a scan to know whether the image will hold up at print size.
• Debugging why an image looks different on two devices - the embedded ICC profile and color tags are often the culprit.
• Recovering the approximate shot location from a photo someone sent you, via embedded GPS tags.

The Privacy Side of EXIF Data

• GPS coordinates reveal where you were. A phone photo uploaded directly to a blog or forum can include latitude and longitude accurate to a few meters - enough to identify your home, a friend\'s apartment, a hotel room, or the exact spot you took a wildlife shot.
• Camera serial numbers tie photos to devices. EXIF tag 0xA431 stores a body serial number. If you have ever posted any photo from that camera with other metadata (your name, your gallery profile), a serial correlation can deanonymize future "anonymous" posts.
• Timestamps reveal patterns. The DateTimeOriginal tag shows capture time to the second. Over many photos this builds a surprisingly detailed schedule of your day.
• Software history is there too. The Software tag often says "Adobe Photoshop 2025" or "VSCO 6.2" or "Snapseed 2.21", exposing your editing toolchain.
• Thumbnail embedded. EXIF can include a small thumbnail that was set at capture. If you edit the main image but not the thumbnail, the thumbnail can reveal pre-edit content - a classic forensic trick.
• Many platforms strip EXIF automatically. Instagram, Facebook, Twitter, and Discord remove most EXIF on upload. Reddit, forum software, self-hosted blogs, and direct email attachments do not. Assume nothing is stripped unless you have verified it.

Why EXIF Exists in the First Place

EXIF (Exchangeable Image File Format) was standardized in 1995 by JEIDA as a way for consumer cameras to embed shooting parameters - exposure, aperture, shutter speed, focal length, ISO - into the photo file itself. The spec grew to cover GPS (EXIF 2.2, 2002), lens ID, and color intent; EXIF 2.32 (2019) adds HDR gain-map support. Adjacent standards coexist in the same file: XMP (Adobe Extensible Metadata Platform, ISO 16684-1) uses RDF/XML for editable metadata; IPTC carries caption and byline data for photojournalists; ICC profiles (ISO 15076) carry the color space definition. A single JPEG from a modern phone may contain all four systems at once.

How This Compares to Desktop Inspectors

ExifTool by Phil Harvey is the gold standard on the command line: it reads and writes hundreds of tag types across every image and video format, including maker-specific tags that document proprietary camera internals. Adobe Bridge, Photo Mechanic, and digiKam provide graphical metadata editors with batch support. Mac Preview\'s "Show Inspector" panel and Windows Explorer\'s Properties > Details tab show the common tags. This tool covers the 80% use case - "what does my photo reveal?" - in a browser tab without installing anything. For deep forensic inspection or editing metadata in place, switch to ExifTool.