What is the CRC file format?
A .crc file is a plain-text checksum sidecar that lists filenames alongside their CRC-32 values, allowing software to verify that files have not been accidentally corrupted during transfer or storage. Each data line follows the pattern FILENAME XXXXXXXX, where XXXXXXXX is an 8-character uppercase hexadecimal CRC-32 value. Lines beginning with ; are comments, commonly recording the generator tool name and creation date.
The .crc extension describes the same Simple File Verification (SFV) format as .SFV; the two are interchangeable. .sfv is the more widely used extension, while .crc is favoured by tools such as CombineCRC and certain archivers. Win-SFV32 by Fantasia Software popularised the format during the Usenet binary-distribution era of the 1990s, when users needed a lightweight way to confirm that multi-part archive sets arrived intact.
CRC-32 is fast to compute but not cryptographically secure - it reliably detects accidental corruption but cannot protect against deliberate tampering. For multi-part archive recovery as well as verification, PAR2 files add the ability to reconstruct damaged or missing segments.
Total Commander (Ghisler Software) can create and verify .crc files. The command-line tool cfv handles .crc and .sfv interchangeably on Windows, macOS and Linux. RapidCRC Unicode is a popular Windows GUI alternative.
Security & safety
RISK: LOWA .crc file is plain ASCII text with no executable code and poses no direct risk. Indirectly: CRC-32 is not cryptographically secure, so a matching CRC does not prove a file was not tampered with - only that it was not accidentally corrupted. For security-sensitive integrity checks, use SHA-256 and a digital signature instead.
Format details
in a nutshell- Binary CRC data file - Some applications store raw binary CRC values in a file with .crc extension - distinct from the SFV text format.
Programs that open CRC files
Windows4 apps
Total Commander
Freemium Files > Calculate Checksums or use the built-in CRC verify function; can both create and verify .crc files. 
CombineCRC
Free Used with multi-part Total Commander-split archives; verifies and combines parts using .crc files. 
RapidCRC Unicode
Free Drag the .crc file onto RapidCRC to verify all listed files in the same folder. 
macOS1 app
Linux1 app
cfv (command-line file verifier)
Open-source cfv -f archive.crc - verifies all files listed in the .crc/.sfv against their CRC-32 values. Technical details
deep spec| Format type | Plain-text CRC-32 checksum sidecar (Simple File Verification) |
| Encoding | ASCII; UTF-8 in modern tools for non-ASCII filenames |
| File signature | None - plain text, no magic bytes |
| Line syntax | FILENAME followed by one or more spaces then an 8-character uppercase hex CRC-32 value |
| Comment syntax | Lines beginning with ; are ignored; typically record generator name and creation date |
| Checksum algorithm | CRC-32 (32-bit cyclic redundancy check) |
| Security | Detects accidental corruption only; not tamper-resistant - CRC-32 collisions are constructible |
| Self-integrity | None - the .crc file itself carries no checksum |
| Typical file size | Under 10 KB (one entry per verified file) |
| Associated OS | Windows, Linux, macOS |
| Related formats | .sfv (identical format, more common extension); .md5, .sha1, .sha256 (stronger hash algorithms); .par2 (adds error recovery) |
| Released | Early 1990s (Usenet binary distribution era); Win-SFV32 by Fantasia Software formalised the format |
| Latest version | No formal version - format unchanged since introduction |
| Open standard | Yes · royalty-free |
| Specification | www.fastsum.com |
CRC conversions
Community Q&A
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