免费 OCR — Image to Text Extractor

工作原理

OCR (Optical Character Recognition) here uses the open-source Tesseract engine — the same engine Google has maintained for decades — compiled to WebAssembly so it runs natively in your browser.

1. 1
   The OCR engine downloads as WebAssembly

   On first use, Tesseract.js loads as a WebAssembly module (~3 MB). It runs inside your browser like native code, with no plugins or extensions needed.
2. 2
   A language model downloads for your chosen language

   Each language has its own trained model (~5-15 MB each, depending on script complexity). You pick the language; only that language's data downloads. Your browser caches it for future use.
3. 3
   You select or paste an image

   The image is read into your browser's memory. Tesseract analyzes the pixel data to identify character shapes — no upload, no API call.
4. 4
   Text is extracted with a confidence score

   For each detected word, Tesseract assigns a confidence percentage. High contrast and clean fonts give 95%+ confidence; messy handwriting or low resolution drops it.

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