File Hash Scanner

Calculate SHA-256, SHA-512, SHA-1, and MD5 checksums for any file. Verify downloads and detect tampering.

3,000+ files hashed

Drag & drop a file here, or

Any file type No size limit • Never uploaded

4 Algorithms

SHA-256, SHA-512, SHA-1, and MD5 calculated simultaneously.

Hash Verification

Paste an expected hash to instantly verify your file.

100% Private

Web Crypto API. Files never leave your device.

What hashes prove

A cryptographic hash is a unique digital fingerprint of a file. If even one byte changes — a single pixel edit, a metadata tweak, a re-save — the hash changes completely. Two files with the same SHA-256 hash are mathematically identical. This makes hashes essential for verifying file integrity, detecting tampering, and proving authenticity in legal, forensic, and compliance contexts. Hash values serve as immutable proof that a file hasn't been altered since the hash was recorded. Learn more in our file hash guide.

How to use it

Calculate the hash of an original file and record it — in a log, a database, or alongside the file. Later, hash the file again and compare the two values. If they match, the file hasn't been modified. All processing uses the browser's SubtleCrypto API — files never leave your device. The tool generates MD5, SHA-1, and SHA-256 hashes simultaneously so you can use whichever algorithm your workflow requires.

Professional use cases

Legal teams use file hashes to establish chain of custody for digital evidence — proving that a photo or document hasn't been altered since collection. Software developers verify downloaded packages against published checksums to detect corruption or tampering. Forensic investigators hash evidence files at the point of acquisition and again before analysis. Compliance teams verify that archived records remain unchanged over time.

Hash vs metadata check

Hashing verifies exact file identity — any change at all produces a different hash. Metadata analysis (via the Authenticity Checker or EXIF Checker) tells you what's inside the file: camera info, timestamps, software traces. Use hashing when you need binary proof that a file is unchanged. Use metadata analysis when you need to understand what happened to an image and whether it was edited.

File hashing is one of the most fundamental tools in digital forensics and data integrity verification. Unlike metadata checks that analyze content within a file, a hash treats the entire file as a single data stream and produces a fixed-length output that's practically impossible to reverse-engineer or forge. SHA-256 is the current standard for security-critical applications, while MD5 remains common for quick integrity checks despite known collision vulnerabilities. For photo-specific integrity workflows, start with a hash to confirm the file is unaltered, then use the Metadata Comparison tool to inspect field-level differences. Visit the photo forensics hub for a complete guide to digital evidence verification, or see the online hash calculator page for algorithm-specific details. For finding visually similar images that may differ at the binary level, use the Duplicate Scanner with perceptual hashing.

Frequently Asked Questions

What is a file hash?

A hash (or checksum) is a fixed-length string of characters generated from a file's contents using a mathematical algorithm. It acts as a unique fingerprint — even changing a single byte in the file produces a completely different hash. This makes hashes ideal for verifying file integrity.

Which hash algorithm should I use?

SHA-256 is the current standard for security and integrity verification. It's used by most software publishers. SHA-512 provides stronger security for high-sensitivity use cases. SHA-1 and MD5 are included for legacy compatibility but are cryptographically broken — don't rely on them for security purposes.

Is my file uploaded to a server?

No. All hash calculations happen entirely in your browser using the Web Crypto API (for SHA) and pure JavaScript (for MD5). Your files never leave your device. This is safe for sensitive files like encryption keys, certificates, or proprietary software.

How do I verify a downloaded file?

Software publishers often provide a SHA-256 hash alongside their download links. After downloading, upload the file here and paste the published hash into the "Verify Hash" field. If it matches, your download is authentic and wasn't corrupted or tampered with during transfer.

Is there a file size limit for hashing?

There's no hard limit — processing happens in your browser using your device's memory. Files up to a few hundred MB work well on most devices. Very large files (1GB+) may take longer but will still process. The time shown in results tells you how long the calculation took.

Why is MD5 considered insecure?

MD5 is vulnerable to collision attacks — it's possible to create two different files with the same MD5 hash. This means MD5 can't reliably prove a file hasn't been tampered with. It's still fine for quick non-security checks (like detecting accidental corruption), but use SHA-256 for any security-related verification.

Can I compare two files?

Yes — scan each file separately and compare their SHA-256 hashes. If the hashes are identical, the files are byte-for-byte identical. If they differ by even one character, the files are different. You can also use the "Download All Hashes" button to save results for later comparison.