OCR to PDF
Convert an image (PNG, JPG) or a scanned, non-selectable PDF into a fully searchable document using Optical Character Recognition.
Drag & Drop Image or Scanned PDF here
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Optical Character Recognition (OCR) is the technology that converts images of text — whether from scanned documents, photographs of printed pages, or digitally created PDFs where text is stored as images — into actual machine-readable, searchable, and copy-pasteable text. Without OCR, a scanned contract is just a picture of words; with OCR, it becomes a fully searchable document where you can use Ctrl+F to find any word, select and copy text, and even convert it to Word format.
PDFLocal's OCR tool uses Tesseract.js, the JavaScript port of Google's industry-leading open-source Tesseract OCR engine. This runs entirely within your browser, meaning your scanned documents are never transmitted to any server. The OCR engine supports over 40 languages including English, Hindi, Tamil, Telugu, Arabic, Chinese, French, German, Spanish, and many more.
How to Convert a Scanned PDF to Searchable Text
- Upload your scanned PDF or image: Drop your file into the upload zone. PDFLocal accepts PDF, JPG, PNG, and TIFF formats.
- Select the language: Choose the primary language of the text in your document from the language dropdown for best accuracy.
- Run OCR: Click "Start OCR". The Tesseract engine processes each page sequentially in your browser. A progress indicator shows which page is being processed.
- Review & Download: Once complete, preview the extracted text and download either the text content as a .txt file or a new PDF with the text layer embedded.
Frequently Asked Questions
How accurate is PDFLocal's OCR technology?
PDFLocal uses Tesseract.js, a WebAssembly port of Google's Tesseract 5 OCR engine, which is widely regarded as one of the most accurate open-source OCR engines available. For high-quality scans of cleanly printed text (such as laser-printed documents, printed books, or typed reports), accuracy typically exceeds 98-99%. For lower quality scans, handwritten text, or documents with complex formatting (multiple columns, tables, mixed fonts), accuracy will be lower. Factors that significantly affect OCR accuracy include: scan resolution (300 DPI or higher is recommended), scan contrast and brightness, page skew (tilted or curved pages), presence of background noise or watermarks, and the complexity of the fonts used. For best results, ensure your scans are straight, well-lit, and at least 300 DPI.
Which languages does the OCR tool support?
The Tesseract OCR engine integrated into PDFLocal supports over 40 languages out of the box, including all major Indian languages (Hindi, Tamil, Telugu, Kannada, Malayalam, Bengali, Gujarati, Marathi, Punjabi), all major European languages (English, French, German, Spanish, Italian, Portuguese, Dutch, Russian, Polish), and many Asian languages (Chinese Simplified, Chinese Traditional, Japanese, Korean, Arabic, Hebrew). For Indian users specifically, the Hindi language model in Tesseract performs particularly well for standard Devanagari script printed documents. Select the appropriate language from the dropdown menu before starting the OCR process for the best accuracy.
Can I perform OCR on a multi-page scanned PDF?
Yes. PDFLocal processes multi-page PDFs page by page, running the OCR engine on each page sequentially. After processing, you can download all the recognized text as a single combined text file, or as a new PDF with a searchable text layer overlaid on the original scanned images (allowing the document to look identical to the original while also being searchable). For very long documents (50+ pages), the OCR process may take several minutes since each page requires CPU-intensive image analysis. We recommend keeping the browser tab active and your computer plugged in for long OCR sessions to prevent interruptions.
Why is the OCR output text sometimes garbled or contains errors?
OCR errors typically stem from one or more of these common causes: The scan quality is too low (below 200 DPI), making it difficult for the engine to distinguish letter shapes. The document has background noise, stamps, or watermarks overlapping the text. The text uses an unusual or decorative font that differs significantly from standard printed typefaces. The scan is rotated or skewed, causing the OCR engine to misalign text baselines. The document mixes multiple languages without the correct language model selected. To improve results, try rescanning at 300+ DPI, ensuring even lighting, selecting the correct primary language, and for slightly tilted scans, using a image editor to straighten the page before uploading.
Does OCR work on handwritten text?
Current versions of Tesseract (including the one used in PDFLocal) are primarily optimized for printed/typed text recognition and have limited capability with handwritten text. For neat, block-letter handwriting, you may get 60-80% accuracy. For cursive or flowing handwriting, accuracy drops significantly. True handwriting recognition (HTR) requires specialised neural network models trained specifically on handwriting datasets, which are computationally expensive and not yet available in a client-side browser tool. If you need to digitise handwritten notes, we recommend taking clear, high-contrast photographs with good lighting and trying the OCR tool — results vary widely depending on handwriting style.
Will the OCR process work without an internet connection?
Once the PDFLocal page has fully loaded in your browser, the OCR tool operates completely offline — no internet connection is required. The Tesseract.js WebAssembly binary and the language data files are downloaded when you first load the page and cached by your browser. Subsequent sessions will use the cached version and do not require downloading again. This makes PDFLocal ideal for scenarios where you need to process sensitive documents in air-gapped or restricted network environments, such as secure office networks, government facilities, or areas with unreliable internet connectivity.
Can I edit the OCR output text before downloading?
Yes. After the OCR process completes, the extracted text is displayed in an editable text area within the interface. You can scroll through the recognised text, manually correct any errors, add or remove content, and then download the corrected version. This human-in-the-loop correction step is recommended for important documents where high accuracy is critical. For internal documents where minor OCR errors are acceptable, you can download directly without reviewing. The editing area supports standard text editing shortcuts (Ctrl+A to select all, Ctrl+C to copy, etc.).
Is my document text stored anywhere after OCR?
No. The OCR process runs entirely within your browser tab's isolated JavaScript environment. The extracted text is temporarily stored in browser memory during the active session and is immediately discarded when you close the tab or navigate away from the page. PDFLocal has no server backend, no database, and no logging infrastructure. Your document content — whether the original scanned images or the extracted text — never leaves your device at any point during the OCR process.