Hash any file — without uploading it.
Drop in a file or paste text to get its MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes instantly. Then paste the official checksum from a download page and confirm your file is exactly what the publisher shipped.
⚡
Native Web Crypto
SHA-1/256/384/512 use your browser's built-in crypto — fast and correct, with MD5 running on a local JS implementation.
✅
Verify instantly
Paste an official checksum and see which algorithm matches — green check, or nothing matches at all.
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Nothing uploaded
Files are read with the File API and hashed on your device. No server, no account, no tracking.
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Drag & drop a file here
or click to browse — any file type, any size your device can handle
How it works
Three steps from file to verified checksum — all on your device.
1
Drop in your file
Drag and drop any file, or click to browse. It's read locally with the File API — nothing is uploaded.
2
Get all five hashes
MD5, SHA-1, SHA-256, SHA-384, and SHA-512 are computed on your device — SHA via the native Web Crypto API, MD5 via local JavaScript.
3
Verify & confirm
Paste the official checksum from the download page. Matching algorithm highlights green; a mismatch means the file differs from what was published.
Where does your data go? Nowhere.
Some online hash tools ask you to upload the very file you're trying to verify — a strange trade for a security tool. This one keeps everything on your device.
Upload-based hash sites
- ✗ The file you're verifying is uploaded to a remote server
- ✗ Files can be copied, logged, or analyzed by third parties
- ✗ Ads, queues, and size caps gate the useful features
- ✗ For a security task, that's a lot of unnecessary trust
Checksum Calculator — 100% client-side
- ✓ Files are hashed on your device with the File API + Web Crypto — nothing uploaded
- ✓ MD5 runs on a local pure-JavaScript implementation
- ✓ No accounts, no ads, no size limits, no watermarks
- ✓ Your files vanish when you close the tab
Who is this for?
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Software users
Verify downloaded installers and ISOs against official SHA-256 checksums before running them.
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Developers
Generate checksums for release artifacts, compare file copies, and check integrity in CI workflows.
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Security-minded users
Check that files haven't been tampered with — without handing the file to another website.
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Archivists & admins
Generate hashes for backup manifests and confirm copies match the originals byte-for-byte.
Frequently Asked Questions
Everything you need to know about hashing and checksums with Prescosoft.
What is a checksum (file hash)? ▾
A checksum, or hash, is a short fixed-length fingerprint computed from a file's exact contents. Any change to the file — even a single byte — produces a completely different hash. That's why software download pages publish hashes: you can compute the hash of the file you downloaded and compare it to the published value to confirm the file is exactly what the publisher shipped.
Which algorithms does the calculator support? ▾
Five: MD5, SHA-1, SHA-256, SHA-384, and SHA-512. SHA-256 is the recommended default for integrity checks today; SHA-512 is stronger and used by many distros; MD5 and SHA-1 are still widely published by older software, even though they're no longer considered cryptographically secure. All five are computed locally in your browser.
Is MD5 still safe to use? ▾
MD5 is fine for detecting accidental corruption, but it is not cryptographically secure — collisions can be crafted deliberately. Prefer SHA-256 or SHA-512 when verifying files that could be targeted by an attacker, like downloaded software. The calculator computes MD5 mainly because many legacy download pages still publish MD5 checksums.
Are my files uploaded to a server? ▾
No. Files are read locally with the File API, the SHA family is computed with your browser's native Web Crypto API, and MD5 runs on a local pure-JavaScript implementation. Nothing is sent anywhere — which is important, because hashing a file is exactly the kind of task you want to do on your own machine. There's no account, no tracking, and nothing is stored after you close the page.
How do I verify a downloaded file's checksum? ▾
Drop the file into the calculator, wait for the hashes, then paste the official checksum into the Verify field. The tool compares it (case-insensitively) against every computed hash and highlights the matching algorithm with a green check — or tells you nothing matches, so you know the file differs from what the publisher shipped.
Is there a file size limit? ▾
There is no artificial limit — the practical limit is your device's memory, since the SHA family is computed by your browser on the file's data. Multi-gigabyte files work on a modern desktop; on phones or low-memory devices, very large files may take a while. Files are read in chunks so the page stays responsive while hashing.
Related Guides
Understand file integrity, privacy, and local processing.
File Converter Websites: The Hidden Privacy Risk
What happens to your files — and your data — when you use online conversion sites, and why local processing is safer.
Read the guide → Beginner GuideHow to Convert Files in the Browser (Without Uploading Them)
Understand how modern browsers process files locally — the same private-by-design pattern this calculator uses.
Read the guide →Related Prescosoft Tools
More privacy-first browser tools for security and file work.