Hash a file or text
Drop a file or paste some text and get its hash with four algorithms. It is for comparing: if your value matches the one published next to a download, you have the same file, byte for byte.
Your text and files stay on your device: nothing is uploaded
Or drop a file here, anywhere on the page.
Result
Paste something on the left: the result appears as you type.
How it works
A hash is a short number that depends on every single byte: change one and the whole thing changes. It is for comparing two files without putting them side by side. The file is read here, one piece at a time, so even one of several gigabytes does not fill up the memory: it just takes a while, and the bar shows how far along it is. MD5 has been broken for twenty years — two different files can be made to share a hash — but it is still what many sites print next to their downloads, so it is here. Use it to compare, never to protect a password.
Frequently asked questions
- How do I check a file I downloaded?
- Drop it on the page, or press “Choose a file”: the file does not leave your device, it is read here one piece at a time. Then compare the value with the same name as the one published next to the download. If they match, the file arrived whole and identical to the original; if they differ by even one character, it did not. One file at a time: if you drop several, the first one is hashed.
- Why doesn’t my hash match the one I expected?
- A single different character is enough: a space, a capital letter, a line break at the end. Each line break counts as one character, even if the original text used Windows ones. And if you computed the other hash with “echo” in a terminal, echo adds a trailing line break: use “echo -n” instead.
- Which of the four values should I look at?
- The one named next to the published checksum. If no name is given, count the characters: MD5 has 32, SHA-1 40, SHA-256 64, SHA-512 128. Results are shown in lowercase; a published value in capitals is the same hash, since case makes no difference in hexadecimal digits.
- Can the text be worked out from its hash?
- Not by calculation: the hash does not contain the text. But a short or predictable text, such as a word or a date, can be found by trying possibilities one by one, and ready-made lists of hashes exist for the most common words. That is why a hash alone hides nothing short or guessable.
- Why does a space or a line break change the hash?
- Because they are characters like any other: a single space has a hash of its own, different from that of empty text and from that of a line break. Here they are hashed exactly as you type them, with nothing trimmed. If two values do not match, check for spaces and line breaks at the end first.
What you paste is never uploaded. Anywhere.
The text you type stays in your browser’s memory: no request goes out while you type. You can paste something confidential.
- Processed locallyEverything happens on this page.
- Nothing to upload, nothing to wait forNothing to upload, no waiting.
- Nothing to deleteWe keep nothing: nothing reaches us.