File Hash Checker: Verify File Integrity with SHA-256 Online
What is a File Hash?
A file hash (or checksum) is a unique fingerprint generated from a file's contents using a mathematical algorithm. Even a single byte change produces a completely different hash. This makes hashes perfect for verifying that a file hasn't been corrupted during download or tampered with by malicious actors.
Common Hash Algorithms
**SHA-256** is the most widely used — it produces a 64-character hex string and is used by software distributors, blockchain, and security tools. **SHA-512** offers even stronger verification with 128 characters. **MD5** is older and faster but considered weak for security — still useful for quick integrity checks where security isn't a concern.
How to Verify a Downloaded File
1. Download the file from the official source. 2. Copy the publisher's checksum (usually listed on their download page). 3. Open the File Hash Checker. 4. Drop your downloaded file into the tool. 5. Compare the generated hash with the publisher's checksum. If they match, your file is authentic and uncorrupted.
When to Use File Hashes
Always verify hashes when downloading: operating system ISOs (Windows, Ubuntu, macOS), security tools and VPN software, cryptocurrency wallets, firmware updates for hardware, and any executable from a third-party website. It takes 5 seconds and can prevent installing compromised software.
Privacy and Security
The FreeCompressKit hash checker processes files entirely in your browser using the Web Crypto API. Your files are never uploaded to any server. The hash is computed locally, making it safe to use even for sensitive documents.