Browser-local utilities

Useful tools. Your data stays yours.

No sign-up. No uploads. Practical tools that run entirely in your browser.

Find a tool

Hash tools & SM3

Hash Calculator

Hash text or files and verify each digest in one place.

Document tools

PDF Text & OCR

Extract text and recognize scans in one local PDF tool.

Image to Text

Recognize English and Chinese text in images locally.

Chinese cryptography

SM2 Tools

Local key generation, encryption, signatures, and format conversion.

SM4 Encryption

Local authenticated encryption with SM4-GCM.

Privacy & FAQ

Are files uploaded?

No. Tool modules download from this site; a local Web Worker processes your files. There is no remote computation API.

How large can files be?

Hash tools process files sequentially in 4 MiB chunks. Limits depend on your browser and device. A 2 GiB zero-filled file has been validated in local Chrome; this is not a limit guarantee for every device. PDF extraction has separate limits listed on its page.

More tools?

PDF text extraction and OCR share one tool. Image OCR, SM2 and SM4 are available. Developer tools will be added gradually.