File inspector

Identify a file by its bytes: true type, size, a SHA-256 fingerprint and quick details like image dimensions or PDF version.

SHA-256file-type

Questions people ask

How do you know what a file is?: By its contents, not just its name. Most file formats begin with a few distinctive "magic bytes", so a .jpg that is really a .png is detected as a PNG, and the tool flags that the extension does not match.
Do you open or edit my file?: No. The inspector reads a small header to identify the format and streams the rest only to compute a SHA-256 fingerprint. It never parses the document's meaning or changes a single byte.
What is the SHA-256 for?: A short, unique fingerprint of the exact bytes. Two files with the same SHA-256 are identical; if a checksum changes, the file changed. It is a reliable integrity check, not a password.
Do you keep my files?: No. The upload is removed as soon as the job finishes. Your inspection report is available for about 10 minutes, then it is automatically deleted too.

About this tool

Detection reads the header "magic bytes" rather than trusting the extension, so a .jpg that is really a PNG comes out as a PNG and the mismatch is flagged. The SHA-256 is a reliable integrity fingerprint: if it changes, the bytes changed. The file is only read, never modified or opened for editing.

File limits

Up to 4 files per job
Each at most 50 MiB
Result at most 1 MiB

Supported formats

Any file type

Capabilities

SHA-256file-type

Privacy & processing

Your file is processed in an isolated job on Tooley's own infrastructure. No third-party services are involved and nothing is stored beyond the result window.

Uploads are removed as soon as processing finishes. Results stay available for about 10 minutes, then they are deleted automatically.