File Checksum Generator
File Checksum Generator is used to calculate file hash values (checksums), supporting five algorithms: MD5, SHA-1, SHA-256, SHA-384, and SHA-512. The tool helps verify file integrity and detect whether files have been tampered with or corrupted.
What is a Checksum
A checksum is a fixed-length string obtained by calculating file content through a hash algorithm. The same file will always produce the same checksum regardless of when or where it's calculated; any minor change to the file content will result in a completely different checksum.
Checksums are widely used for:
- Verifying downloaded file integrity
- Detecting whether files have been tampered with
- Confirming files haven't been corrupted during transmission
- Comparing whether two files are identical
Supported Algorithms
MD5 (Message Digest Algorithm 5)
128-bit hash value, fast computation speed, but lower security, not suitable for security-sensitive scenarios.
Output length: 32 characters (128 bits)
Commonly used for: File integrity verification, non-security scenario unique identification
SHA-1 (Secure Hash Algorithm 1)
160-bit hash value, more secure than MD5 but still has collision risks, gradually being replaced by SHA-256 and other more secure algorithms.
Output length: 40 characters (160 bits)
Commonly used for: Git version control, legacy system compatibility requirements
SHA-256 (SHA-2 Series)
256-bit hash value, high security, widely used in modern security scenarios.
Output length: 64 characters (256 bits)
Commonly used for: Digital signatures, certificate verification, blockchain, cryptographic applications
SHA-384 (SHA-2 Series)
384-bit hash value, security between SHA-256 and SHA-512.
Output length: 96 characters (384 bits)
Commonly used for: Applications requiring higher security levels
SHA-512 (SHA-2 Series)
512-bit hash value, currently the highest security level SHA-2 algorithm.
Output length: 128 characters (512 bits)
Commonly used for: High security requirement applications, large file integrity verification
How to Use
- Click upload area or drag and drop file
- Select hash algorithm (MD5, SHA-1, SHA-256, SHA-384, SHA-512)
- Wait for calculation to complete
- View generated checksum result
- Click copy button to get checksum value
Application Scenarios
Verifying Downloaded Files
After downloading software or image files from websites, use the tool to calculate file checksum and compare with officially provided checksum to confirm file hasn't been tampered with or corrupted.
File Integrity Check
After transferring large files, calculate checksum to confirm file hasn't been corrupted or lost data during transmission.
Duplicate File Detection
By comparing file checksums, quickly determine whether two file contents are identical without byte-by-byte comparison.
Version Management
Generate checksums for different versions of files to quickly identify whether files have changed.
Data Backup Verification
Calculate checksums after backing up data, regularly verify backup file integrity to ensure data recoverability.
Usage Tips
Choosing the Right Algorithm
MD5: Fast computation, suitable for quickly verifying non-sensitive files, but not suitable for security scenarios.
SHA-1: Good compatibility, but limited security, gradually being phased out, not recommended for new projects.
SHA-256: High security, moderate computation speed, recommended for most scenarios.
SHA-384 and SHA-512: Highest security, suitable for high security requirement scenarios, but longer computation time.
Verifying Downloaded Files
After downloading files, find the provided checksum value on the official website, calculate local file checksum using the same algorithm, and compare whether they match. Complete match indicates file hasn't been tampered with and transmission is complete; mismatch indicates file may be corrupted or modified.
Large File Processing
Calculating checksums for large files (several GB) requires considerable time, please be patient. SHA-512 algorithm takes longest for large files.
Saving Checksum Records
After generating checksums for important files, it's recommended to save results to a separate text file for future verification.
Important Notes
All calculations are completed locally in the browser, files are not uploaded to servers, protecting privacy and security.
Hash algorithms are one-way; original file content cannot be derived from checksums.
Two different files may rarely produce the same checksum (hash collision), but in SHA-256 and higher algorithms, collision probability is extremely low and can be ignored.
Browser processing of large files may consume considerable memory; it's recommended to close other resource-intensive tabs.
Frequently Asked Questions
Why is the calculation result different from what's provided officially$1
Possible reasons include:
- Different algorithm selected (confirm algorithm used officially)
- File corrupted during download (re-download)
- File has been tampered with (re-download from official source)
- File is not the same version (confirm version number)
Which is better, MD5 or SHA-256$2
SHA-256 security is far superior to MD5. If only for quickly verifying non-sensitive file integrity, MD5 is sufficient and faster; if involving security verification or anti-tampering scenarios, must use SHA-256 or higher-level algorithms.
Can text content be verified$3
This tool only supports file checksum calculation. If you need to calculate hash values for text content, it's recommended to save text as a file first, then process with the tool.
Will two different files have different checksums$4
Yes. Hash algorithm characteristics ensure that even if a file has only one byte difference, the calculated checksum will be completely different.
Browser freezes when calculating large files$5
Processing extremely large files (10GB+) may cause browser to consume large amounts of memory. It's recommended to use specialized command-line tools (like md5sum, shasum) to process extremely large files, or process files in segments.
Can checksums encrypt files$6
No. Checksums are hash values used to verify file integrity, not encryption. Hashing is one-way and cannot restore file content from checksums. File encryption requires specialized encryption tools.
