What is this file, really?
Read the bytes, not the name. Find mismatched extensions, hidden GPS and what is making a file big.
A file extension is a claim, not a fact. Anyone can rename a WEBP to .jpg, and the photo your camera saved carries far more than the picture. This reads the first bytes of the file to see what it actually is, then opens up everything stored alongside the image.
What it tells you
- The real format, read from the file signature rather than the name.
- Whether the extension is lying, which is the usual reason an upload is rejected.
- Dimensions, colour depth, duration, bitrate and codec.
- Camera, lens, shutter, ISO and the exact capture time from EXIF.
- GPS coordinates, if the photo still carries them.
- Where the bytes went, so you can see why a 6MB photo is 6MB.
Why an extension can be wrong
- Saving from a browser often keeps the page’s name and not the real type.
- Messaging apps re-encode images but keep the original filename.
- Renaming a file never changes a single byte inside it.
Questions
How can a file have the wrong extension?
Because the extension is only part of the name. Renaming photo.webp to photo.jpg changes nothing inside the file, so a strict uploader reads the bytes, sees WEBP, and rejects it.
Does this show GPS location from a photo?
Yes, when the photo still has it. Phones write the coordinates into EXIF, and most photos shared straight from a camera roll still carry them.
Is my file uploaded to check it?
No. The bytes are read inside your browser tab. Nothing is sent anywhere.