File Hash Calculator
Compute MD5, SHA-1, SHA-256, SHA-512 and SHA3-256 hashes of pasted text or an uploaded file, all at once, in hex (lowercase/uppercase, with or without colons) — and verify against an expected hash.
Input
Any file type. Read locally in your browser — never uploaded. Used only when the text box is empty.
Hash algorithms
Options
Comparison ignores case, colons, dashes and spaces.
Output
| Algorithm | Hash |
|---|---|
| No data yet | |
Only shown when an expected hash is provided.
Guides
The File Hash Calculator computes cryptographic hashes — MD5, SHA-1, SHA-256, SHA-512 and SHA3-256 — of an uploaded file or a block of pasted text, all in one pass. Every selected algorithm's digest appears together in a results table, so you can compare several checksums for the same input at once instead of running the tool repeatedly.
A hash is a one-way fingerprint: the same input always produces the same fixed-length output, but the output can't be reversed back into the original data. That makes hashing the standard way to verify that a downloaded file hasn't been corrupted or tampered with, confirm two files are byte-for-byte identical, or check a value against a publisher-supplied checksum.
How to use it
- Paste text into the input box, or upload a file — whichever has content is what gets hashed (the text box takes priority when both are filled).
- Tick the algorithms you want. MD5, SHA-1 and SHA-256 are checked by default; SHA-512 and SHA3-256 are available too.
- Pick a hash format: lowercase hex, UPPERCASE hex, or either with colon separators (
ab:cd:ef…) — the format many tools use when displaying certificate fingerprints or MAC addresses. - Read the computed hash for each algorithm in the results table, or copy/download the whole table as CSV.
Verifying a published checksum
Paste a hash into the Expected hash field and the tool checks it against every algorithm you selected, reporting which one matched (or that none did). The comparison ignores case, colons, dashes and spaces, so you can paste a hash in whatever format the publisher used — a raw hex string, a colon-separated fingerprint, or an uppercase digest — without reformatting it first.
Which algorithm should I use?
- SHA-256 is the safest general-purpose choice today, and what most modern download pages publish alongside a file.
- MD5 and SHA-1 are fast but cryptographically broken — an attacker can construct a different file with the same hash. They're offered here purely for interoperability with older checksums and signatures that still use them, not for anything security-sensitive.
- SHA-512 and SHA3-256 are useful when a system specifically asks for them, or when you want a wider digest than SHA-256 provides.
Does it hash the whole file, even a large one?
Yes — the file is read into memory in your browser and hashed in a single pass, so extremely large files (many hundreds of MB or more) may be slow or hit browser memory limits. For everyday downloads, installers and documents, it's effectively instant.
Privacy
Everything runs entirely in your browser using the audited open-source @noble/hashes library. Your file or text is never uploaded to a server — it's hashed locally and discarded when you leave the page, so it's safe to use on sensitive or confidential files.
Use it from code
From 3 credits per callREST API
curl -X POST https://api.iotools.cloud/v1/tool/file-hash-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"inputText": "abc",
"file": "",
"algoMd5": "true",
"algoSha1": "true",
"algoSha256": "true",
"algoSha512": "",
"algoSha3": "",
"hashFormat": "lowercase",
"expectedHash": ""
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `file-hash-calculator` tool (File Hash Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.