File Hash Comparison Tool
Compare two files side by side to check whether they are identical, or verify a single file against a published checksum. Supports MD5, SHA-1, SHA-256, SHA-384 and SHA-512. Nothing is uploaded.
💡 SHA-256 is selected by default. Enable more algorithms to compare across multiple hash functions.
crypto.subtle.digest for SHA algorithms and an embedded MD5 implementation. Files are never uploaded. If two files have the same hash for a given algorithm, they are, with overwhelming probability, byte-for-byte identical.
💡 Finding This Comparison Tool Useful?
Get the standalone version — a single HTML file you can keep on your machine and open anytime, with no internet connection required.
🛒 Get the Standalone Version🔍 What Is a File Hash Comparison Tool?
A File Hash Comparison Tool computes cryptographic hashes of two files and compares the results to determine whether the files are identical. A hash is a fixed-length string derived from the file's contents: even a one-byte change produces a completely different hash. This makes hashing the fastest and most reliable way to check file integrity, detect duplicates, or verify that a download matches a published checksum. This tool supports five algorithms — MD5, SHA-1, SHA-256, SHA-384 and SHA-512 — and runs entirely in your browser. Your files are read locally and never transmitted.
✨ Key Features
Two Comparison Modes
File vs File compares two files side by side. Hash vs File verifies a single file against a pasted checksum.
Five Algorithms
MD5, SHA-1, SHA-256, SHA-384 and SHA-512. Compute any combination simultaneously and compare across all of them.
Automatic Hash Detection
In Hash vs File mode, the tool reads the length of the pasted hash and identifies which algorithm it belongs to.
Visual Match Verdict
A clear match/mismatch banner, plus a per-algorithm table showing which hashes agree and which do not.
Copy & Export
Copy the comparison result as text, or download a JSON file with all hashes and file metadata.
Nothing Leaves Your Device
Files are read with the FileReader API and hashed in the page. There is no backend and no upload.
📖 How to Use the File Hash Comparison Tool
- Choose a mode — File vs File to compare two files, or Hash vs File to verify against a known checksum.
- Load your file(s) — drag and drop, or click to browse. In Hash vs File mode, paste the known hash first.
- Select algorithms — SHA-256 is on by default. Enable others if you need them.
- Click Compare files — hashing starts automatically and the verdict appears when done.
- Read the result — a green banner means the files match; a red banner means they differ.
- Copy or download — save the result as text or JSON for your records.
🎯 Practical Use Cases
Verifying Downloads
Check that a downloaded file matches the checksum published by the vendor.
Finding Duplicates
Two files with the same hash are, with overwhelming probability, identical — even if their names differ.
Backup Integrity
Compare a file against its backup to confirm the copy succeeded without corruption.
Build Verification
Confirm that a rebuilt binary matches the original by comparing their hashes.
Release Publishing
Generate hashes for a release and verify that mirrored copies are identical.
Forensic Comparison
Confirm that two evidence files are byte-for-byte identical using multiple hash algorithms.
⚠️ Important Notes and Limitations
A few honest caveats worth knowing:
• MD5 and SHA-1 are cryptographically broken. They are fine for detecting accidental corruption, but do not rely on them alone for security-sensitive comparisons. Use SHA-256 or stronger when tampering is a concern.
• Large files are read into memory. The tool reads each file as an ArrayBuffer before hashing. Files under about 100 MB are comfortable. Very large files (hundreds of MB) may be slow or fail on devices with limited memory.
• A matching hash does not prove a file is safe. It proves the file matches whatever hash you compared against. If the published hash was wrong, or if an attacker replaced both the file and the published hash, a match means nothing.
• Two files with different hashes are definitely different. But two files with the same hash are only almost certainly identical — hash collisions are theoretically possible, though astronomically unlikely for SHA-256 and above.
• The MD5 implementation is pure JavaScript. It is correct but slower than native implementations. SHA algorithms use the browser's native Web Crypto API and are fast.
❓ Frequently Asked Questions
No. The tool has no backend. Files are read with the browser's FileReader API and hashed in the page using crypto.subtle.digest for SHA algorithms and an embedded MD5 implementation. You can confirm this by opening your browser's network panel while using the tool — no request is made with your file data.
It means the files are, with overwhelming probability, byte-for-byte identical. Even a single changed byte would produce a completely different hash for any of these algorithms. For SHA-256 and above, the probability of a collision is so small that it can be safely ignored for practical purposes. For MD5 and SHA-1, collisions are theoretically findable but still extremely unlikely to occur by accident.
SHA-256 is the right default for almost everything — it is fast, widely supported, and not vulnerable to known practical attacks. Use SHA-512 if you want a larger digest and your toolchain supports it. Use MD5 or SHA-1 only when comparing against a checksum that was published with those algorithms. For security-sensitive comparisons, never rely on MD5 or SHA-1 alone.
It reads the length of the pasted hash and matches it against the known output lengths: MD5 produces 32 hex characters, SHA-1 produces 40, SHA-256 produces 64, SHA-384 produces 96, and SHA-512 produces 128. The tool tells you which algorithm it thinks the hash belongs to, and then compares it against the computed hash of that same algorithm.
There is no hard-coded limit, but each file is read into memory as an ArrayBuffer. Files under about 100 MB are handled comfortably. Larger files may be slow or fail on devices with limited memory. This is a browser limitation, not specific to this tool.
No. Nothing is stored. The files are held in memory only while the comparison runs, and the results are displayed in the page. When you close or refresh the page, everything is gone. The standalone edition works the same way, with no local storage used.
👨💻 About the Author — GenieDevs
📦 Get the Standalone Version
⚖️ File Hash Comparison Tool – Standalone Edition
One self-contained HTML file with the full comparison tool inside. Keep it on your machine, run it from a USB stick, or use it on an air-gapped computer — no internet connection needed.
✅ Final Takeaway
Whether you are verifying a download, checking a backup, or hunting for duplicate files, hashing is the most reliable way to answer the question "are these the same?" This tool makes that comparison fast and visual — load two files, see a clear verdict, and know that the answer is based on the actual bytes, not on filenames or timestamps. Everything runs in your browser, so nothing you compare leaves your machine.