What type of file is this?
Drop a file and Morphr reads its magic bytes — the signature at the very start of the file — to tell you what it actually is, whether its extension is honest, and what you can convert it to. Locally, with nothing uploaded.
Drop a file to identify it
Read locally — only the first 512 bytes are inspected, and nothing is uploaded.
Detection reads only the first 512 bytes of each file, entirely in your browser. Nothing is uploaded.
Why the extension can lie
A file's extension — the .jpg or .pdf at the end of its name — is just a label, and anyone
can change it by renaming the file. The bytes inside don't change when you rename it. So a screenshot saved as
photo.png that was actually exported as a JPEG is still a JPEG; only its name says otherwise. That mismatch
is why an image sometimes refuses to open, or why an upload form rejects a file that looks fine.
What a magic number is
Most formats start with a short, fixed sequence of bytes that identifies them — a magic number or
signature. PNG files open with the bytes 89 50 4E 47 (the second three spell “PNG”), JPEG with
FF D8 FF, PDF with the text %PDF, and ZIP-based files — including Word, Excel and EPUB — with
PK. Reading just those first bytes is enough to recognise the format with confidence, no matter what the
file is called.
Frequently asked
- How can you tell a file type without the extension?
- Most file formats begin with a fixed sequence of bytes called a magic number or signature — JPEG starts with FF D8 FF, PNG with the bytes ‰PNG, PDF with %PDF. Reading those first bytes reveals the true format regardless of what the file is named.
- My file has the wrong extension — what does that mean?
- It usually means the file was renamed. A photo saved as “image.png” that actually starts with JPEG's signature is really a JPEG. Identifying the real type tells you which program will open it and what you can safely convert it to.
- Is my file uploaded when I identify it?
- No. Detection runs entirely in your browser and reads only the first 512 bytes of the file. Nothing is sent to a server — the same local-only model as the rest of Morphr.
- Why does it say “ZIP archive” for my Word or Excel file?
- Modern Office files (.docx, .xlsx, .pptx), OpenDocument files and EPUB e-books are all ZIP archives of XML inside. The ZIP signature is detected from the content; the specific Office type is then inferred from the file name.
Once you know what a file is, read its format guide or convert it — both run entirely in your browser.