Tool Capabilities

This tool calculates and compares cryptographic hashes for files or text inputs. You can either upload files or paste text, select a hash algorithm (like MD5, SHA-1, SHA-256), and compare the generated hash against an expected hash value. It's crucial for verifying data integrity, ensuring files haven't been corrupted or tampered with.

• Calculates hashes for uploaded files using various algorithms (MD5, SHA-1, SHA-256, SHA-512)
• Calculates hashes for direct text input
• Compares the generated hash against a user-provided expected hash
• Supports multiple hash algorithms simultaneously for comparison
• Handles large files efficiently using browser-based processing (streaming)
• Provides clear visual feedback on whether the hashes match or mismatch
• Works entirely offline, keeping your files and data private

Common Use Cases

1. Verifying Software Downloads

   Compare the hash of a downloaded installer or archive against the hash provided by the vendor to ensure the file is authentic and wasn't corrupted or tampered with.

2. Ensuring File Integrity After Transfer

   Calculate a hash before transferring a large file (e.g., via FTP, USB drive), and verify it after the transfer to confirm no data corruption occurred.

3. Detecting File Tampering

   Check if a critical file stored locally or on a server matches its original known hash to detect unauthorized modifications or malware infections.

4. Validating Backup Integrity

   Compare the hash of a backup file (e.g., database dump, zip archive) against the hash of the original data source to ensure the backup is complete and uncorrupted.

5. Comparing ISO Images

   Verify the integrity of downloaded operating system ISO images or other large disc images by comparing their hash against the official checksum.

6. Checking Configuration Consistency

   Compare the hash of configuration files across different servers or environments to ensure they are identical.

7. Verifying Text Snippets

   Ensure a piece of text (e.g., a public key, a code snippet, a license key) exactly matches an expected value by comparing hashes.

8. Auditing File Changes

   Periodically calculate hashes of important files and compare them against previously recorded hashes to detect any changes over time.

9. Duplicate File Detection (Concept)

   Use hash comparison as a primary method to identify potential duplicate files across directories or drives before performing slower byte-by-byte checks.

10. Confirming Data Synchronization

    After syncing data between two locations (e.g., cloud storage, local folders), compare hashes of key files to confirm synchronization was successful.

Technical Details

For files, the tool uses the browser's FileReader API, often in conjunction with the SubtleCrypto API (Web Cryptography API), to read the file in chunks (streaming) and progressively calculate the hash. This allows processing large files without loading the entire content into memory. For text input, the text is encoded (typically to UTF-8) and then hashed using SubtleCrypto.digest(). The calculated hash (in hexadecimal format) is then compared case-insensitively against the user-provided expected hash. All calculations happen client-side.