Voice & Speech

tesseract.js

Pure Javascript OCR for more than 100 Languages 📖🎉🖥

Status
Generally available
Last checked
Aging · Sep 4, 2026
License
Open source
Pricing
Free tier · from $0
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What it is

tesseract.js is a pure JavaScript library that enables Optical Character Recognition (OCR) in web applications, supporting over 100 languages. It allows developers to extract text from images directly within the browser.

tesseract.js stands out for its pure JavaScript implementation, making it ideal for browser-based applications where server-side dependencies are not desired.

When it fits — and when it doesn’t

A good fit for

  • Developers building web applications where text extraction from images is required without server-side dependencies

  • Projects needing to support multiple languages for OCR in a browser environment

Look elsewhere if

  • Applications requiring real-time OCR processing at very high volumes, as performance may be limited by the client's hardware

  • Use cases that require integration with non-JavaScript environments without additional effort

Known weaknesses

Each one links to the public issue, changelog or docs page it came from, where we have one.

  1. 01

    Performance degradation with large images

    Processing large or high-resolution images can lead to significant performance drops and increased memory usage in the browser.

  2. 02

    Limited customization for advanced OCR features

    The library provides basic OCR functionality but lacks advanced settings such as page segmentation modes, which are available in the original Tesseract engine.

  3. 03

    Dependence on WebAssembly for performance

    Performance relies heavily on WebAssembly, which may not be supported or optimized equally across all browsers and devices.

  4. 04

    Limited documentation and examples

    The official documentation lacks detailed guides and examples for complex use cases, making it harder to implement advanced features.

What it does well

  • Pure JavaScript implementation for browser compatibility

  • Supports over 100 languages

  • High accuracy in text recognition from images

Pricing

Free tier
YesOpen source — free to use
Paid from
$0
Model
Flat rate
Enterprise plan
No

Pricing not independently confirmed — check the vendor’s page.

Performance benchmarks

How Fast Is It?

Set up tesseract.js

Setup steps, common gotchas and what to check after 30 days.

Open the setup guide →