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.

Free Online PDF OCR Text Recognition - Multi-language·Local Processing

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.

📋 How to Use

Upload PDF File — Click the upload area or drag and drop a PDF file. Multi-page PDFs are supported.

Select Recognition Language — Choose the primary language in the PDF (Chinese, English, etc.). Multi-language combinations are available.

Start Recognition — Click 'Start Recognition' and wait for the OCR engine to process each page. Copy or download the results when done.

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.

❓ Frequently Asked Questions

Is PDF OCR Text Recognition free to use?

Yes, PDF OCR Text Recognition is completely free to use. No registration or login required — all features are available immediately.

Can I use PDF OCR Text Recognition on my phone?

Yes. PDF OCR Text Recognition is fully responsive and works on phones, tablets, and desktops. The interface adapts automatically to your screen size.

Do I need to install any software?

No. PDF OCR Text Recognition is a web-based tool — just open it in your browser and start using it. No downloads, plugins, or extensions required.

Is my data safe when using PDF OCR Text Recognition?

Absolutely. All processing happens locally in your browser. No data is sent to any server, so there's zero risk of data leaks. Your information stays completely under your control.

Are there any usage limits for PDF OCR Text Recognition?

PDF OCR Text Recognition has no usage limits — it's free and unlimited. Since processing is done client-side, speed depends on your device. For very large files, we recommend processing in batches for the best experience.

Will the PDF quality decrease after processing?

We preserve original quality whenever possible. For compression, you can choose the compression level to balance file size and quality.