Stamp a File

Select a file to calculate its salted SHA256 hash. A secure random salt will be generated in your browser and combined with the file bytes before hashing. The file will be processed locally in your browser and the hash will be sent to the server for inclusion in a block. Once included, you can prove that the file existed at the time of the block.

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Click to select a file or drag and drop

No file selected

🔒 The file is processed locally in your browser and never uploaded to any server. The salt is generated securely in your browser and only the salted hash is sent to the server.