What Is OCR (Optical Character Recognition)?
Optical Character Recognition (OCR) is a technology that converts images containing text — such as scanned documents, photos of signs, screenshots, or handwritten notes — into machine-readable, editable text. Our tool uses Tesseract.js, the JavaScript port of Google's legendary Tesseract OCR engine, which is one of the most accurate open-source OCR engines in the world. It runs entirely in your browser, meaning your images are never uploaded to any server.
Common Use Cases for OCR
OCR technology has countless practical applications in daily life and business:
- Digitizing receipts: Snap a photo of a receipt and extract the text for expense tracking or bookkeeping.
- Document conversion: Convert scanned PDFs, printed articles, or book pages into editable text.
- Screenshot text extraction: Pull text from screenshots of chat conversations, error messages, or web pages that don't allow copy-paste.
- Handwritten notes: Convert handwritten notes to digital text (accuracy varies with handwriting clarity).
- Data entry automation: Extract data from forms, invoices, or business cards to reduce manual typing.
Tips for Best OCR Accuracy
While modern OCR engines are remarkably accurate, the quality of your input image directly affects results. Follow these tips to maximize accuracy:
- Resolution: Use images with at least 300 DPI. Higher resolution means sharper character edges for the engine to detect.
- Contrast: Dark text on a light background works best. Avoid low-contrast combinations.
- Orientation: Keep text horizontal. Significantly rotated or skewed text reduces accuracy.
- Font size: Text smaller than 10pt in the original document is harder to recognize. Zoom in or crop the relevant section.
- Clean images: Remove noise, shadows, and background patterns when possible.
Supported Languages
Our OCR tool supports nine major languages out of the box: English, Hindi, Spanish, French, German, Simplified Chinese, Japanese, Korean, and Arabic. Language data is downloaded on first use (typically 1–15 MB depending on the language) and cached by your browser for subsequent uses. Tesseract.js supports 100+ languages — we've selected the most commonly requested ones for ease of use.
Frequently Asked Questions
How accurate is the OCR?
For clean, printed text at good resolution, Tesseract.js typically achieves 95–99% character accuracy. Handwritten text, artistic fonts, or low-quality images will have lower accuracy. The confidence score shown after processing gives you a reliable indicator of result quality.
Why does the first scan take longer?
On first use (or when switching languages), the tool downloads the Tesseract language data file (~1–15 MB). This data is cached by your browser, so subsequent scans in the same language are much faster. You'll see a download progress indicator during this initial setup.
Are my images sent to a server?
No. All OCR processing happens entirely in your browser using Tesseract.js WebAssembly. Your images never leave your device, making this tool completely safe for sensitive documents like medical records, financial statements, or personal correspondence.
Can I extract text from PDFs?
This tool works with image files (JPEG, PNG, WebP, BMP). If you need to extract text from a scanned PDF, first convert the PDF pages to images (using a screenshot or our PDF tools), then use this OCR tool on each page image.