whatfiletypeisthis.com
About whatfiletypeisthis.com
A fast, no-upload file type identifier that explains what a file is used for—and how we detect it.
What this site does
whatfiletypeisthis.com helps you figure out what a file is, even when the name looks weird or the extension is missing. When you drop a file into the tool, it checks the file header (sometimes called magic bytes) to identify the format. If you paste an extension (like .heic or .db), it explains what that extension usually means and what apps commonly create it.
Why we built it
Most “file type checkers” either send your file to a server or only guess based on the extension. We wanted something fast, private, and simple: identify the file type online for free, without uploading your file.
How detection works (simple version)
Many formats start with a recognizable signature. For example, JPEG images begin with a consistent header pattern, and PDF files start with %PDF. The tool reads a small portion of the file locally in your browser and compares it to known signatures. When a match is found, we show the type, typical extensions, what it’s used for, and what commonly creates it.
Other tools we run
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