A scanned document looks like a PDF but it is not searchable. The text is stored as a flat image — pixels arranged to look like letters, not actual characters. You cannot select a word, copy a sentence, or run Ctrl+F to find a section. Optical Character Recognition (OCR) reads those pixels and converts them into real text, making the document searchable, accessible, and copyable.
This matters for lawyers searching 500-page deposition transcripts, HR teams indexing employee records, researchers working through digitised archives, and anyone who has ever needed to find a number in a scanned bank statement. PDFKits OCR PDF processes your scanned documents in your browser, adding a searchable text layer over the image without altering the visual appearance of any page.
Drag your scanned PDF into the tool. The tool confirms the file is image-based — if it already has a text layer (meaning OCR has been run previously or it was created from a digital source), the tool will note that. For best results, scans should be at 150 DPI or higher and reasonably straight — a page photographed at a 30-degree angle will produce poor recognition results.
OCR accuracy depends on the language model. Select the primary language of the text in your document — English, French, Spanish, German, Portuguese, Russian, Chinese, or others. For mixed-language documents, select the dominant language. Running OCR with the wrong language selected produces garbled output where characters are misread as visually similar letters from a different script.
Click Run OCR. The tool analyses each page, identifies text regions, and builds a searchable text layer. OCR accuracy for clean, well-aligned printed text is typically 97–99%. Handwritten notes, unusual fonts, very small print, or low-contrast scans reduce accuracy. The output PDF looks identical to the input but now has selectable text — open it and press Ctrl+F to verify the search works. Processing a 30-page scan at typical resolution takes about 20–60 seconds depending on your device.
A litigation paralegal receives a 600-page deposition transcript as a scanned PDF from an opposing party. Running OCR on it in PDFKits makes the entire document searchable — she finds every reference to a key date by pressing Ctrl+F, a task that would otherwise require reading every page manually.
A historian digitising 1940s administrative records photographs 200 typed pages and converts them to PDFs. OCR transforms the image-based pages into searchable documents — names, dates, and places are now full-text indexed, making cross-document research practical.
A clinic digitises patient intake forms from the past decade. OCR makes patient names, dates of birth, and condition codes searchable within the document archive, dramatically reducing the time to retrieve specific records.
An accounting firm scans 10 years of paper invoices as part of a compliance audit. OCR on each batch makes vendor names, invoice numbers, and amounts searchable — auditors can find any transaction in seconds rather than browsing scan by scan.
A student working on a comparative literature thesis downloads digitised books as image PDFs from a university library. Running OCR makes the texts searchable, enabling her to find every occurrence of a specific term across three 400-page volumes simultaneously.
OCR has traditionally required dedicated software — ABBYY FineReader costs $199 for a perpetual licence, Adobe Acrobat Pro charges $29.99/month, and most online OCR services upload your documents to cloud servers for processing. PDFKits runs OCR directly in your browser using Tesseract.js, the browser port of the industry-standard Tesseract OCR engine.
| Feature | PDFKits | Adobe Acrobat Pro | ABBYY FineReader | ILovePDF OCR |
|---|---|---|---|---|
| Cost | Free, always | $29.99/month | $199 perpetual | 2 tasks/day free |
| Files stay on your device | Yes | No — cloud | Yes | No — cloud |
| Multilingual support | Yes | Yes | Yes | Limited |
| No installation required | Yes | No | No | Yes |
| Daily limit | Unlimited | Unlimited | Unlimited | 2/day |
For confidential documents — patient files, legal correspondence, financial records — browser-side OCR is the only approach that guarantees the document content never reaches an external server.
OCR (Optical Character Recognition) converts image-based PDFs into searchable documents. You need it when you cannot select or search text in a PDF — usually because it was scanned from paper.
For clean, well-aligned printed text at 150 DPI or higher, accuracy is typically 97–99%. Handwriting, unusual fonts, very small text, or low-quality scans reduce accuracy significantly.
English, French, Spanish, German, Portuguese, Russian, Chinese (Simplified and Traditional), Italian, Dutch, Arabic, and many more via the Tesseract language models.
No. OCR processing runs entirely in your browser using Tesseract.js. Your scanned documents never leave your device.
No. The visual appearance of each page remains identical. OCR adds an invisible text layer underneath that makes text selectable and searchable.
150 DPI is the minimum for acceptable accuracy. 200–300 DPI is recommended for documents with small fonts or dense tables. Photos taken with a phone are usually sufficient if the image is clear and straight.
OCR is optimised for printed text. Handwriting recognition is significantly less accurate and depends heavily on how legible the handwriting is.
Yes. PDFKits will add OCR to pages that are image-based while leaving existing text layers on digital pages intact.
Yes, but OCR on mobile is significantly slower than on desktop due to processing power constraints. A 10-page scan may take 1–2 minutes on a smartphone.
Garbled output usually means the wrong language was selected, the scan resolution is too low, or the document has unusual fonts. Try re-running with the correct language and a higher-quality scan.