Free Online Checksum Calculator

A checksum calculator computes MD5, SHA-1, SHA-256 and SHA-512 digests of a file in a single pass, the standard way to verify downloaded software integrity.

Your data is processed entirely in your browser and never sent to any server.

Instant results 100% private No signup needed

Drop a file here, or click to pick one

Hashed locally — your file never leaves the browser.

How to Use This Tool

  1. Drop a file onto the upload area, or click it to pick one.
  2. Wait a moment while all four digests compute (MD5, SHA-1, SHA-256, SHA-512).
  3. Compare the digest you need against the publisher's posted value character-for-character.
  4. Click Copy next to any digest to send that value to your clipboard.

What Is a Checksum Calculator?

A checksum is a short fixed-length fingerprint of a file's contents. If even one byte of the file changes, the checksum changes completely thanks to the avalanche property — so by comparing the checksum you computed locally to the value the publisher posted, you can confirm a download arrived intact and untampered. This is the standard workflow for verifying ISO images, language-runtime installers, container images and CLI tools.

Different algorithms suit different needs. MD5 (RFC 1321) is the fastest but cryptographically broken — fine when you trust the source against accidental corruption but useless against an adversary. SHA-1 (FIPS 180-4) is deprecated for cryptographic use but still posted by some older projects. SHA-256 (FIPS 180-4) is the modern default and what most publishers list today. SHA-512 is sometimes used for very large artefacts.

This tool reads the file with the browser's `FileReader` and computes all four digests in a single pass via the Web Crypto API (plus a pure-JS MD5). Your file never leaves the device. For multi-gigabyte inputs give it a moment; memory bandwidth, not CPU, is usually the bottleneck.

Frequently Asked Questions

What's the difference between checksum and file-hash?
This tool computes all four common digests at once, side by side. The file-hash tool focuses on one algorithm at a time.
Why verify a checksum?
To confirm a downloaded file hasn't been corrupted or tampered with. Compare your hash against the publisher's posted value.
Is there a file size limit?
The file is read in chunks in your browser, so it scales with available memory. Multi-GB files work but may take a moment.

Published by the WeGotEveryTool team. We build and test every tool in-house and update pages when the underlying spec, formula, or recommendation changes.

Reviewed: May 2026. Disclaimer: this tool is provided as-is for general informational use. For decisions with material consequences (medical, legal, financial, security) verify results against a qualified professional source.

Related Encryption & Security

MD5 Hash Generator

Generate MD5 hash from text. One-way hashing for checksums and non-security uses.

SHA-256 Hash Generator

Generate SHA-256 hash from text. Secure 256-bit hashing for integrity and verification.

SHA-512 Hash Generator

Generate SHA-512 hash from text. Stronger 512-bit hashing for high-security needs.

File Hash Calculator

Hash a file with a single algorithm — MD5, SHA-1, SHA-256 or SHA-512. Useful for verifying downloads.

HMAC Generator

Generate HMAC (keyed-hash MAC). Verify integrity and authenticity with a shared secret key.