Labs · 🟢 Local sample verified · 1 November 2026 · Viewer and cleaner compared
PNG metadata lab: where do text chunks and GPS live?
Can a PNG carry a location and a caption, and are those chunks gone after a local clean?
A PNG can carry eXIf, text chunks, and sometimes C2PA. The local sample showed location-style fields, and the cleaned copy did not. The .png extension is not proof of a clean file. Clean the copy in this browser before sending. The file stays on this device and is not uploaded to this site.
Screenshots and exports are often PNG. People treat that as pixels only. The file can still carry location and text, and some files carry provenance.
Short answer
Direct answer: the local PNG sample exposed location-style fields, and the cleaned copy no longer had them.
- What was measured: On 1 November 2026 the viewer read GPS and camera-style fields in the local PNG sample. The cleaner copy omitted them and the file got smaller without repainting the image data.
- What that does not prove: Clearing text chunks does not erase an address that is drawn in the picture, and it does not describe an app’s servers.
- What you can do first: Clean the copy in this browser before the file leaves the device. Nothing is uploaded to this site.
🟢 Local sample verified · 1 November 2026 · Viewer and cleaner compared
- Published
- Last updated
- Last tested
What we measured
Sample dated 2026-11-01. The viewer read location and camera fields. The cleaned file no longer has them. The file stayed on this device.
| Field | Local sample (viewer) | Cleaned copy (cleaner) |
|---|---|---|
| GPS / location | 35 deg 0' 0.00" N, 135 deg 0' 0.00" E | No GPS |
| EXIF | EXIF present (camera make, model, and settings) | EXIF fields cleared |
| Camera information | Camera make and model present | Camera make and model removed |
| Timestamps | 2026:11:01 18:00:00 | Capture time removed |
| Provenance / C2PA | No C2PA or JUMBF container | No C2PA or JUMBF container |
| Recompression / resize | 2,617,629 bytes, with location and the metadata above | 2,616,357 bytes; metadata removed, image scans unchanged |
GPS / location
The viewer read 35 deg 0' 0.00" N, 135 deg 0' 0.00" E. The cleaned file had no GPS.
EXIF
The viewer read a camera make, a model, and the capture time 2026:11:01 18:00:00. The cleaned file had no EXIF.
Test environment
Chrome 156.0.8078.47 and ExifTool 12.76. The file stayed on this device. Nothing was uploaded.
How to test your own file
- Inspect a PNG from a camera export and one from a generator.
- List chunk types.
- Do not confuse textual chunks with C2PA.
Methodology
Every published result has to follow the same protocol: a known source file, a recorded hash, a specific upload path, and a downloaded copy. Folklore does not count.
Privacy implications
AI tools that export PNG may leave generator text in chunks. Inspect the file, do not assume PNG is clean.