Hash / Checksum Tool
Generate cryptographic and non-cryptographic hashes of text using the Web Crypto API and a local CRC32 implementation.
Runs locally in your browser
Processed locally in your browser.
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What is the Hash / Checksum Tool?
This tool computes SHA-256, SHA-384 and SHA-512 hashes of text or a local file using the browser’s Web Crypto API. It also shows a CRC32 checksum for text.
How to use it
- 1Enter text or choose a local file up to 25 MB.
- 2Read the computed hashes for each algorithm.
- 3Copy any digest.
How it works
SHA digests are produced by crypto.subtle.digest over the UTF-8 bytes of your input. CRC32 is computed with a standard lookup-table algorithm in JavaScript.
Limitations & notes
- Files are limited to 25 MB in this browser interface; CRC32 is available for text only.
- MD5 is intentionally omitted as it is broken for security use.
Frequently asked questions
How do I verify a downloaded file against a published SHA-256 checksum?
Choose the downloaded file in the file field, copy the SHA-256 value the tool shows, and compare it with the checksum on the vendor's download page. Every one of the 64 hex characters must match; a single different character means the file is corrupted or not the one published. Comparison is not case-sensitive, since this tool prints lowercase hex while some sites print uppercase.
Why is my hash different from the one my command line gives?
Hashes change completely if even one byte differs. The most common cause is a trailing newline: echo hello | sha256sum hashes hello plus a line break, while typing hello here hashes five bytes. Windows CRLF line endings, a leading space, or a different text encoding cause the same mismatch. This tool hashes the exact UTF-8 bytes in the text box, with nothing added.
What is the difference between CRC32 and SHA-256?
CRC32 produces an 8-hex-character checksum designed to catch accidental errors, such as a corrupted transfer, and it is used inside ZIP and PNG files. It is easy to forge on purpose. SHA-256 produces 64 hex characters and is built so nobody can practically create two inputs with the same digest. Use CRC32 only for quick integrity checks; for security or download verification use SHA-256 or stronger.
Can I use SHA-256 from this tool to store passwords?
You should not. SHA-256 is deliberately fast, so attackers can test billions of guesses per second against a leaked hash, and an unsalted hash of a common password can be found in precomputed tables. Passwords belong in a slow, salted algorithm such as Argon2id, bcrypt or scrypt. Use these SHA digests for checksums, deduplication and verifying that content has not changed.
Does the tool show MD5 or SHA-1, or CRC32 for files?
No. It shows SHA-256, SHA-384 and SHA-512 for both text and files, and adds CRC32 only for typed text. MD5 is not offered because it is broken for security use, and SHA-1 is not computed here either, so if a vendor publishes only an MD5 or SHA-1 checksum you will need another utility. Files must be smaller than 25 MB.
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