CRC32 Generator & Checker – Free Online CRC32 Checksum Tool

Compute CRC32 checksums from any text string or file — entirely in your browser, with no upload required. The text tab updates the checksum in real time as you type. The file tab accepts any file type via click or drag & drop and computes its CRC32 fingerprint client-side using the IEEE 802.3 polynomial (0xEDB88320). Choose your output format: hex (e.g. 414FA339), unsigned decimal, or signed decimal (PHP-compatible). Use the built-in Verify panel to compare the computed checksum against an expected value and confirm file integrity. The same algorithm used internally by ZIP, gzip, PNG, and Ethernet. Perfect for developers, sysadmins, and anyone verifying download integrity or detecting data corruption.

Output Format

Input
Type or paste text to compute its CRC32 checksum
CRC32 Checksum
Your CRC32 checksum will appear here as you type…
🔒 100% in-browser — no data is ever sent to any server

Try an example

About CRC32: Uses the IEEE 802.3 polynomial (0xEDB88320). The hex output is the most common format used in tools like zip, gzip, and PNG. CRC32 is a checksum, not a cryptographic hash — it is fast and designed for error detection, not security.

How to Use the CRC32 Generator & Checker

Compute CRC32 from text:

  1. Stay on the Text / String tab (default).
  2. Type or paste any text — the CRC32 checksum updates instantly as you type.
  3. Choose your preferred output format: Hex (e.g. 414FA339), Unsigned Decimal, or Signed Decimal.
  4. Click any format card in the result panel to switch output on the fly.
  5. Click Copy to copy the current value to your clipboard.

Compute CRC32 of a file:

  1. Click the File Upload tab.
  2. Click the upload area or drag & drop any file — any type, any size.
  3. The CRC32 is computed entirely in your browser. Nothing is uploaded to any server.
  4. Once computed, the result appears in all three formats — switch freely between them.

Verify / compare a CRC32 checksum:

  1. After computing a checksum, the Verify / Compare panel appears.
  2. Paste the expected checksum — hex (with or without 0x prefix), unsigned decimal, or signed decimal are all accepted.
  3. Click Verify (or press Enter) — the tool instantly shows Match or Mismatch.
  4. A match confirms the content is bit-for-bit identical to the source.

What is CRC32 and when should you use it?

  • CRC32 (Cyclic Redundancy Check, 32-bit) is a fast checksum algorithm using the IEEE 802.3 polynomial (0xEDB88320).
  • ✅ Good for: verifying file integrity, detecting accidental data corruption (used internally by ZIP, gzip, PNG, Ethernet, and many firmware formats).
  • ❌ Not for: security — CRC32 is trivially reversible and not collision-resistant. Use SHA-256 or SHA-512 for security-sensitive applications.
  • Output formats: Hex is the standard format shown by most tools. Unsigned decimal is a positive integer (0 to 4,294,967,295). Signed decimal is PHP's crc32() output (may be negative on 32-bit systems).
  • CRC32 of 123456789 is CBF43926 — the standard test vector defined in ISO 3309.