tesseract.js
Advanced tools
tesseract.js is a JavaScript library that provides Optical Character Recognition (OCR) capabilities. It allows you to extract text from images and PDFs directly in the browser or in a Node.js environment.
Basic OCR
This feature allows you to perform basic OCR on an image file. The code sample demonstrates how to recognize text from an image using the English language.
const Tesseract = require('tesseract.js');
Tesseract.recognize(
'path/to/image.png',
'eng',
{
logger: m => console.log(m)
}
).then(({ data: { text } }) => {
console.log(text);
});Handling Multiple Languages
This feature allows you to recognize text in multiple languages. The code sample demonstrates how to recognize text from an image using both English and Spanish languages.
const Tesseract = require('tesseract.js');
Tesseract.recognize(
'path/to/image.png',
'eng+spa',
{
logger: m => console.log(m)
}
).then(({ data: { text } }) => {
console.log(text);
});Progress Reporting
This feature provides real-time progress updates during the OCR process. The code sample demonstrates how to log progress messages to the console.
const Tesseract = require('tesseract.js');
Tesseract.recognize(
'path/to/image.png',
'eng',
{
logger: m => console.log(m)
}
).then(({ data: { text } }) => {
console.log(text);
});Using Worker for Performance
This feature allows you to use a worker for better performance, especially for large images or multiple OCR tasks. The code sample demonstrates how to create a worker, load the necessary language, perform OCR, and then terminate the worker.
const { createWorker } = require('tesseract.js');
const worker = createWorker({
logger: m => console.log(m)
});
(async () => {
await worker.load();
await worker.loadLanguage('eng');
await worker.initialize('eng');
const { data: { text } } = await worker.recognize('path/to/image.png');
console.log(text);
await worker.terminate();
})();ocrad.js is a JavaScript port of the OCRAD OCR library. It is designed to be used in the browser and can recognize text from images. Compared to tesseract.js, ocrad.js is lighter but may not be as accurate or feature-rich.
node-tesseract-ocr is a Node.js wrapper for the Tesseract OCR engine. It provides a simpler interface for performing OCR in Node.js environments. While it offers similar functionalities to tesseract.js, it does not support browser usage.
Tesseract.js is a javascript library that gets words in almost any language out of images. (Demo)
Image Recognition
Video Real-time Recognition
Tesseract.js wraps a webassembly port of the Tesseract OCR Engine. It works in the browser using webpack, esm, or plain script tags with a CDN and on the server with Node.js. After you install it, using it is as simple as:
import { createWorker } from 'tesseract.js';
(async () => {
const worker = await createWorker('eng');
const data = await worker.recognize('https://tesseract.projectnaptha.com/img/eng_bw.png');
console.log(data.text);
await worker.terminate();
})();
When recognizing multiple images, users should create a worker once, run worker.recognize for each image, and then run worker.terminate() once at the end (rather than running the above snippet for every image).
Tesseract.js works with a <script> tag via local copy or CDN, with webpack via npm and on Node.js with npm/yarn.
<!-- v5 -->
<script src='https://cdn.jsdelivr.net/npm/tesseract.js@5/dist/tesseract.min.js'></script>
After including the script the Tesseract variable will be globally available and a worker can be created using Tesseract.createWorker.
Alternatively, an ESM build (used with import syntax) can be found at https://cdn.jsdelivr.net/npm/tesseract.js@5/dist/tesseract.esm.min.js.
Requires Node.js v14 or higher
# For latest version
npm install tesseract.js
yarn add tesseract.js
# For old versions
npm install tesseract.js@3.0.3
yarn add tesseract.js@3.0.3
Version 5 changes are documented in this issue. Highlights are below.
createWorker arguments changed
createWorker
createWorker("chi_sim", 1)worker.initialize and worker.loadLanguage functions now do nothing and can be deleted from codeUpgrading from v2 to v5? See this guide.
Version 4 includes many new features and bug fixes--see this issue for a full list. Several highlights are below.
createWorker is now asyncgetPDF function replaced by pdf recognize optionThe following are old examples that use depreciated versions of Tesseract.js. Updating to Tesseract.js v4 is highly recommended. Users are encouraged to create updated examples (or make entirely new ones) and submit them as pull requests.
React Native is not supported as it does not support Webassembly.
To run a development copy of Tesseract.js do the following:
# First we clone the repository
git clone https://github.com/naptha/tesseract.js.git
cd tesseract.js
# Then we install the dependencies
npm install
# And finally we start the development server
npm start
The development server will be available at http://localhost:3000/examples/browser/demo.html in your favorite browser.
It will automatically rebuild tesseract.min.js and worker.min.js when you change files in the src folder.
You can use Gitpod(A free online VS Code like IDE) for contributing. With a single click it will launch a ready to code workspace with the build & start scripts already in process and within a few seconds it will spin up the dev server so that you can start contributing straight away without wasting any time.
To build the compiled static files just execute the following:
npm run build
This will output the files into the dist directory.
This project exists thanks to all the people who contribute. [Contribute].
Become a financial contributor and help us sustain our community. [Contribute]
Support this project with your organization. Your logo will show up here with a link to your website. [Contribute]
FAQs
Pure Javascript Multilingual OCR
The npm package tesseract.js receives a total of 23,094 weekly downloads. As such, tesseract.js popularity was classified as popular.
We found that tesseract.js demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 4 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
RubyGems.org has added a new "maintainer" role that allows for publishing new versions of gems. This new permission type is aimed at improving security for gem owners and the service overall.
Security News
Node.js will be enforcing stricter semver-major PR policies a month before major releases to enhance stability and ensure reliable release candidates.
Security News
Research
Socket's threat research team has detected five malicious npm packages targeting Roblox developers, deploying malware to steal credentials and personal data.