Online SHA-1 Hash Calculator Tool
Calculation Details
Calculate SHA-1 values for text and files with hash verification, batch processing and Hex/Base64 output
Online SHA-1 Hash Calculator Tool
SHA-1 maps data of any length into a 160-bit digest, commonly represented as 40 hexadecimal characters. This tool quickly calculates SHA-1 values for text and files and is commonly used for legacy systems, Git object identifiers and historical checksum verification.
Core Features
- Text calculation: calculate instantly while typing or switch to manual mode. Displays character count, byte length and line break statistics with examples for empty text, Chinese text and multi-line content.
- File calculation: drag or select files and calculate SHA-1 using 4MB chunk streaming with progress and remaining time display. GB-level files are supported.
- Hash verification: compare the expected hash value with the calculated result. If the length does not match, the tool can suggest possible algorithms.
- Batch calculation: process multiple text lines and generate SHA-1 values for each item.
Output Length and Formats
SHA-1 produces a 160-bit digest, equal to 20 bytes. Hex format contains 40 characters, while Base64 uses 28 characters. The commonly mentioned 40-character SHA-1 value refers to hexadecimal characters, not binary bits. Hex supports uppercase switching and Base64 provides a more compact representation suitable for JSON or HTTP transmission. Results support multiple copy formats and TXT, JSON and CSV export.
Processing Capability
The tool automatically selects the best available calculation engine. WebAssembly implementations or browser native APIs are preferred, with JavaScript compatibility libraries as fallback options. Calculation details display the actual engine, processing time and chunk size used. Large files may require additional time depending on browser capability.
Error Handling
Missing files, failed file reads, unsupported browser features or failed calculation modules provide clear messages. Verification mode checks whether both the calculated result and expected value exist before comparison to avoid incorrect failures.
Use Cases
- Compare results with legacy APIs and systems requiring SHA-1.
- Verify file or data package integrity.
- Check Git commit and object identifiers.
- Learn differences between hash lengths and encoding formats.
Security Notice
SHA-1 has been broken by practical collision attacks and should not be used for digital signatures, certificates or new security systems. New applications should use SHA-256, SHA-512 or SHA-3. Password storage should use bcrypt or Argon2.
Privacy and Security
This tool performs all calculations locally in your browser. Text and files are never uploaded or stored on any server.
Calculate SHA-1 digests for text and files online
- Three modes: text calculation, file calculation and hash verification
- Text mode calculates instantly and displays character, byte and line statistics
- File mode uses 4MB chunk streaming with GB-level file support and progress information
- Output supports Hex and Base64 formats with uppercase Hex switching
- Batch calculation generates SHA-1 values for multiple text lines
- Export TXT, JSON and CSV files with calculation engine and timing information