Use the free Batch Hash Generator below: your data never leaves your browser — all work happens on your device, and nothing is uploaded to any server.
A hash turns any text into a fixed-length fingerprint. Change one letter and the fingerprint changes completely, which is why hashes are used to check downloads, store passwords safely, and spot altered records. Hashing one value at a time is fine for a single check, but real jobs come in lists: a hundred usernames, a batch of file names, or a set of coupon codes. The Batch Hash Generator hashes every pasted line at once with the browser’s built-in WebCrypto API and returns one hash per line in a table.
This is deliberately a batch tool, and that distinction matters. Single-text hash tools answer one question: what is the hash of this value? This tool answers a list question: what are the hashes of all these values, side by side, in order, ready to download as a CSV file? If you only have one value, a single-text tool is simpler. If you have ten or five hundred, pasting the list once beats running a single tool five hundred times.
To use it, paste one value per line into the box. The sample holds three short values. Choose an algorithm: SHA-256 is the standard choice for most jobs, SHA-384 and SHA-512 are stronger variants, and SHA-1 is included only for checksum comparisons with older systems. Press Hash all lines. The table appears below with each input beside its hash, and the CSV download keeps the same pairing for a spreadsheet.
A hash is one-way, and that property is the whole point. You cannot turn a SHA-256 hash back into the original text, which is why systems store password hashes instead of passwords. It also means a hash is not encryption: there is no key and no decryption step. Anyone with the same input and the same algorithm gets the same hash, so hashes prove that two values match, but they do not hide a value from someone who can guess it. Short, guessable values like password123 can be matched by trying common guesses, which is why real password systems add a salt and a slow hashing step that this simple tool does not.
Algorithm choice deserves a plain explanation. SHA-1 is broken for security use: researchers have built two different inputs with the same SHA-1 hash, so it should only verify checksums from older systems that still use it. SHA-256 has no such known break and is the safe default. SHA-384 and SHA-512 are stronger but produce longer hashes, which is fine for storage and awkward for reading aloud. For comparing files or records, any of the SHA-2 family works. For anything an attacker might target, use SHA-256 or stronger and never SHA-1.
Empty lines are skipped, because an empty value would hash to a real-looking fingerprint for nothing, which could confuse a later comparison. Lines keep their exact text, including spaces inside the line, but leading and trailing spaces on a line are part of the value in most hash tools, so check for stray spaces when two hashes differ unexpectedly. Copying from a spreadsheet often adds invisible trailing spaces, and those change the hash.
People use batch hashing to verify lists of codes, to prepare test fixtures with hashed identifiers, to compare a list of values against a list of known hashes, and to teach how hashing works with several examples at once. Because the work happens in the browser with WebCrypto, your values never leave the device, nothing is uploaded, and closing the page clears the list from view.
How to hash many lines at once
- Paste one value per line into the box.
- Choose the algorithm, SHA-256 for most jobs.
- Press Hash all lines and check the table.
- Compare hashes, or press Download CSV to save the pairs.
- If two hashes differ unexpectedly, check for stray spaces in the inputs.
Frequently asked questions
Can I turn a hash back into the original text? No. Hashing is one-way by design. Matching works by hashing the candidate and comparing the results.
Which algorithm should I choose? SHA-256 for most jobs. SHA-1 only for checksums from older systems, never for security.
Why is a known value’s hash different here? A stray space, a capital letter, or a line ending changes the input, and any change changes the hash completely.
Are my values uploaded? No. WebCrypto runs in your browser, and nothing is sent or stored.
Paste the list, hash it all at once, and keep the pairs. For batch work, that one step replaces an afternoon of single-value hashing.