What file is this?
Drop a file to see what it really is: the format, read from its first bytes, and the extension it should have. Your browser opens it on your device: nothing is uploaded.
What it tells you
| Read from | The first bytes (the signature), the parts inside a ZIP, the first lines of text |
| How sure | Certain, likely or unknown |
| Shows | The signature bytes, marked |
| Fixes | Download as with the right extension |
| Damage | Says when a file stops short or its header is broken |
| Upload | None: read on your device |
How to find out what a file is
Drop the file in the box above. webdave reads its first bytes, where most formats write a signature, and names the format, says how sure that is, marks the signature bytes and gives the extension the file should have. Download as saves a copy with that name.
- Drop the file. Choose it, drop it or paste it. Its name does not matter: a file with no extension or the wrong one works the same.
- Read the answer. Details names the format and says how sure: certain for a signature, likely for text formats read from their first lines. The signature bytes are marked, here and under Bytes.
- Fix the name. Download as saves a copy with the right extension. View opens it, and Open in sends it to another webdave tool.
Questions
Drop it here. Most formats begin with a signature, a few fixed bytes such as 89 50 4E 47 for PNG or %PDF for PDF. webdave reads them, looks inside ZIPs for Word, Excel and PowerPoint parts, and reads text formats from their first lines.
Apps, chats and downloads sometimes save a WebP as .jpg, strip the extension, or add .bin or .dat. The contents do not change, so the bytes still say what it is.
The first bytes a format always starts with, so programs can tell files apart without trusting the name. A ZIP starts with PK, a GIF with GIF89a, a JPEG with FF D8 FF.
The file starts with no signature webdave knows. Recover then looks through it for pictures, PDFs, Office files and other files hidden inside.
No. It is read in your browser, on your device. Nothing is sent anywhere.