What languages are supported for OCR recognition?

Supports 100+ languages including Simplified Chinese, Traditional Chinese, English, Japanese, Korean, and more. The first time you use a language, the training data (a few MB) will be automatically downloaded and cached in your browser. Multi-language recognition takes longer, so single-language is recommended.

How accurate is the OCR recognition?

Accuracy depends on the image quality of the PDF. Clear scanned documents can achieve 95%+ accuracy, while blurry or handwritten documents have lower accuracy. Tips: 1) Use high-resolution scans; 2) Ensure text is clear and not tilted; 3) Select the correct recognition language.

📄 PDF OCR Text Recognition
中文 EN

Q: Is my PDF data uploaded to a server?

Absolutely not! This tool uses Tesseract.js to run OCR recognition locally in your browser. All PDF files and recognition results are processed on your device. Nothing is uploaded to any server. You can disconnect from the internet to verify the tool still works.

Q: What's the difference between OCR and PDF text extraction?

PDF text extraction can only get existing selectable text in the PDF, suitable for electronic documents. OCR recognition analyzes images to identify text, suitable for scanned documents and image PDFs where text cannot be selected. If the PDF text is selectable, use the PDF text extraction tool for faster and 100% accurate results.

Q: What size PDF files are supported?

Depends on available browser memory. We recommend PDF files under 20MB. Each page takes about 5-15 seconds to recognize. For very large files, we suggest splitting them into smaller files first.

Free online OCR for scanned PDFs. Supports Chinese, English, Japanese, Korean. Client-side processing, no data upload.

Upload PDF File

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Click or drag and drop a PDF file here

Supports .pdf files, recommended under 20MB

Recognition Settings

Recognition Language

FAQ

Q1: Is my PDF data uploaded to a server?

Absolutely not! This tool uses Tesseract.js to run OCR locally in your browser. All PDF files and results are processed on your device. Nothing is uploaded to any server.

Q2: What languages are supported?

Supports 100+ languages including Simplified Chinese, Traditional Chinese, English, Japanese, Korean, and more. The first time you use a language, training data (a few MB) will be downloaded and cached.

Q3: How accurate is the OCR?

Accuracy depends on PDF image quality. Clear scanned documents can achieve 95%+ accuracy. Tips: Use high-resolution scans, ensure text is clear and not tilted, select the correct language.

Q4: What's the difference between OCR and PDF text extraction?

PDF text extraction only gets existing selectable text, suitable for electronic documents. OCR analyzes images to identify text, suitable for scanned documents and image PDFs. If text is selectable, use text extraction for faster and 100% accurate results.

Q5: What size PDF files are supported?

Depends on browser memory. We recommend files under 20MB. Each page takes about 5-15 seconds. For very large files, split them first.

📄 PDF OCR Text Recognition 中文 EN