Hash generator and file checksum
Type text or choose a file to get its SHA-256, SHA-512, SHA-384 and SHA-1 hashes, and paste a hash to check that it matches.
Free · no signup Runs in your browser
How do I get the SHA-256 hash of a file?
Choose File, pick the file and its SHA-256, SHA-512, SHA-384 and SHA-1 hashes appear. To check a download, paste the hash the publisher gave you into the compare box: if it matches one of the hashes, the file is the one they published. The file is read on your device and is never uploaded.
What a hash is, and what it is for
A cryptographic hash turns any amount of data into a short fixed-length fingerprint. The same input always gives the same hash, and changing even one character changes the whole hash. It cannot be reversed to recover the input.
The main everyday use is checking a download. Software publishers list the SHA-256 hash of each file; after downloading, you compute the hash of your copy and compare. If they match, the file arrived intact and unaltered. If they differ, the download was corrupted or tampered with, and you should not run it. Developers also use hashes to detect duplicates and changes, and as one ingredient of digital signatures.
It runs in your browser. Files are read on your device and are never uploaded.
How it works in detail
The tool uses the browser's built-in SubtleCrypto.digest, so the results are the same as those from command-line tools such as sha256sum. Text is first turned into bytes as UTF-8, and a file is read as its raw bytes. You get SHA-1 (40 hexadecimal digits), SHA-256 (64), SHA-384 (96) and SHA-512 (128). A hash is a fixed-length fingerprint of the data: changing even one byte gives a completely different result, and the hash cannot be turned back into the data. To check a download, paste the hash the publisher gave you into the compare box: it is compared with each result, ignoring case and spaces, and you are told whether one matches. SHA-1 is shown for checking old downloads only, because it is no longer considered secure against deliberate attack. MD5 is not offered, because the browser's cryptography does not include it. Large files are read into memory, so very large files may not work on small devices.
How to use it
- Choose Text or A file.
- Type or paste your text, or choose the file.
- Read the hashes. Tick upper-case hexadecimal if the publisher shows them in capitals.
- To verify a download, paste the published hash into the compare box and read the match result.
- Copy the hash you need.
What changes and what stays the same
What the tool does with your input, and what it leaves alone.
| Aspect | What happens |
|---|---|
| The data | Not changed or stored; only its fingerprint is shown |
| Text | Read as UTF-8 bytes, so the hash matches other tools only if they also hash UTF-8 |
| Case of the hash | Hexadecimal digits are the same in upper or lower case; the tick box only changes how they are shown |
| Files | Hashed from their raw bytes, so a renamed file has the same hash |
| Reversibility | None: a hash cannot be turned back into the data |
| Privacy | Everything is worked out in your browser; what you type or choose is not uploaded or saved |
When to use it
- Checking that a downloaded installer matches the publisher's hash
- Finding out whether two files are identical
- Getting the hash of a string for a test
- Comparing a file before and after a transfer
Problems you may run into
Most problems come from the input, not from the tool.
| What you see | Likely cause | What to do |
|---|---|---|
| My hash differs from the one on the website | The file is different or damaged, or the wrong algorithm is being compared | Download the file again, and compare with the algorithm the site names (often SHA-256) |
| My text hash differs from another tool | A trailing space or line break, or a different text encoding | Check for a hidden new line at the end; this tool uses UTF-8 |
| I need MD5 | The browser's cryptography does not include it | Use SHA-256 where you can; for a legacy check, use a command-line tool |
| The page slows down on a big file | The whole file is read into memory | Use a desktop tool for very large files |
| Is a hash a safe way to store passwords? | A plain SHA hash is fast to guess against | Use a password-hashing function such as Argon2, bcrypt or scrypt in your own software |
| Nothing happens after I paste | The box is empty, or the text was copied as an image | Copy the text again from the source and paste it into the box |
Mistakes it helps you avoid
- Using a hash as encryption: it is one-way and hides nothing about short, guessable text.
- Storing passwords as plain SHA-256: password storage needs a slow, salted method.
- Comparing a hash from the same page as the download: a hash only helps if you trust where it came from.
- Pasting a hash with extra spaces or the wrong case: the comparison ignores case and spaces.
How it works
Everything happens in your browser as you type.
hash = SHA-1, SHA-256, SHA-384 or SHA-512 of the bytes (text is read as UTF-8)length = SHA-1 is 40 hexadecimal digits, SHA-256 is 64, SHA-384 is 96, SHA-512 is 128check = your pasted hash is compared with each result, ignoring case and spacesone-way = a hash cannot be turned back into the data
The hashes are computed with the browser's built-in SubtleCrypto.digest, so they are the same as those from command-line tools such as sha256sum. SHA-1 is shown for checking old downloads only; it is no longer considered secure against deliberate attack. MD5 is not offered because the browser's cryptography does not include it. Large files are read into memory, so very large files may be slow on a phone.
Example: the SHA-256 of 'hello'
You hash the five letters hello.
- Inputhello
- SHA-2562cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824
- Add one letter: HelloA completely different hash
Always the same 64 digits for hello
Try it to see the avalanche effect.
Terms on this page
- Hash
- A fixed-length fingerprint of data that changes completely if the data changes.
- Checksum
- A hash used to check that a file arrived intact.
Common questions
What is a file checksum?
A hash of the file's contents. If your copy gives the same hash as the publisher's, the file is identical.
Is SHA-256 secure?
Yes, SHA-256 is widely used and has no known practical attack. SHA-1 is not considered secure against deliberate attack and is shown only for old downloads.
Why is MD5 missing?
The browser's built-in cryptography does not include MD5, and MD5 is considered broken for security uses.
Is my file uploaded?
No. It is read and hashed on your device.
Can a hash be reversed?
No. A hash is one-way, though short or common inputs can be guessed by trying many.
Where these numbers come from
- MDN Web Docs — SubtleCrypto.digest() How a browser computes SHA hashes.
- NIST FIPS 180-4, Secure Hash Standard (SHS) The standard that defines SHA-1, SHA-256, SHA-384 and SHA-512.
- MDN Web Docs — Clipboard API How a page copies text to your clipboard when you press a button.
Last verified 2026-10-25 The method on this page is checked against the sources above at least once a year. Spotted something out of date? Tell us and we will fix it.
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