Check what a file really is
Drop any file and see what it really is, judged from its content rather than its name. You also get size, dimensions, number of images, codec and a basic integrity result.
Drop images here, or pick them from your device
Stays on your device. Nothing is uploaded.
Processing on this device
How to use it
- Drop one or more files onto the page. HEIC, JPEG, PNG, WebP, AVIF, GIF, BMP and TIFF are recognised.
- Read the detected type next to the extension to spot mismatches.
- Check size, dimensions, number of images in the file and codec.
- If something looks wrong, follow the link to the health check or repair tool.
What it keeps
- Your file is only read. Nothing is modified or saved.
- Everything stays on the device.
What it removes or changes
- Nothing in the file changes. This tool produces a report only.
Limits
- The integrity check is basic. It is not a full decode test. The health check goes further and tries a real decode.
- It tells you what the file is, not whether the picture is good.
- Limits: 200 MB per file.
Compatibility
Use it when an app refuses a picture, a download has an odd extension, or a phone export says .heic but behaves differently. Because detection is by content, it catches renamed files, such as a JPEG saved as .heic, which many programs reject.
Privacy
Only the start and structure of the file are inspected, locally in your browser. The file is not uploaded and is not stored.
File checker, health check or inspector?
The checker is the quick first look: what is this and how big is it. The health check is for suspected problems like truncation or unsupported codecs, and tries a decode. The inspector is for people who want the inner structure, such as brands, grids and auxiliary images. Start with the checker, and move to the others only if the answer is not enough.
Troubleshooting
It says the type is JPEG but the file is named .heic.
The file was renamed or exported incorrectly. Rename it .jpg and it should open normally.
It reports an unknown type.
The file may be damaged, not an image, or a format outside the supported list. Run the health check.
The checker says OK but the photo will not open.
The integrity check is basic. The health check attempts a real decode and gives a recommendation.
Frequently asked questions
Does it trust the file extension?
No. It reads the content of the file to find the real type, so a renamed file is reported for what it is.
Which formats can it identify?
HEIC, JPEG, PNG, WebP, AVIF, GIF, BMP and TIFF.
Can it fix a broken file?
No. For recovery use the repair tool.