PDF OCR - Make Scanned PDFs Searchable
Add an invisible text layer to your scanned PDFs using Optical Character Recogni...Add an invisible text layer to your scanned PDFs using Optical Character Recognition. Once processed, every page becomes fully searchable with Ctrl+F,...
Drop your scanned PDF here, or click to browse
Make scanned documents searchable and copyable
Supported Formats
Input Formats
Output Formats
OCR Engine Capabilities
Production-grade text recognition for scanned documents of any complexity
Why Use PDF OCR - Make Scanned PDFs Searchable?
Invisible Text Layer Technology
OCR maps each recognized character to its exact pixel coordinates on the scanned image, then embeds an invisible Unicode text layer beneath it. Your PDF viewer reads this hidden layer for search and selection, while displaying the original scan. The result is a hybrid PDF where every word is machine-readable but the document looks untouched. This is the same technique used by Adobe Acrobat and enterprise scanning solutions.
PDF/A-3 Compliant Output
Output files conform to PDF/A-3 archival standards, the ISO 19005-3 specification required by government agencies, courts, and regulated industries for long-term document preservation. PDF/A-3 ensures your searchable PDFs remain readable decades from now, regardless of which software opens them. This is critical for legal discovery, medical records, and financial compliance.
Section 508 & WCAG Accessibility
The embedded text layer makes scanned documents accessible to screen readers, satisfying Section 508 (US federal) and WCAG 2.1 AA requirements. Visually impaired users can navigate OCR-processed PDFs with assistive technology. Many organizations are legally required to make their document archives accessible - OCR is the first essential step.
Full-Text Search Across Every Page
After OCR processing, press Ctrl+F (Cmd+F on Mac) to search for any word, phrase, date, or number across hundreds of pages instantly. Document management systems like SharePoint, Google Drive, and Dropbox can also index the embedded text, making your scanned archives discoverable through their search features.
95-99% Accuracy on Quality Scans
Clean scans at 300 DPI with standard printed fonts achieve recognition accuracy between 95% and 99%. Our OCR engine handles serif, sans-serif, monospace, and common business fonts reliably. For degraded or historical documents, built-in image preprocessing (deskewing, binarization, noise removal) can recover accuracy that would otherwise be lost.
100+ Languages Including RTL Scripts
Full support for Latin, Cyrillic, CJK (Chinese, Japanese, Korean), Arabic, Hebrew, Devanagari, Thai, and dozens more scripts. Right-to-left languages are handled with correct text direction in the embedded layer. Select your document's primary language for optimal recognition, or let the engine auto-detect for mixed-language documents.
Real-World OCR Applications
How organizations use OCR to unlock content trapped in scanned documents
Corporate Document Archive Digitization
A law firm scanning 50,000 case files from filing cabinets needs every document searchable for e-discovery. OCR converts each scanned page into a searchable PDF so attorneys can find specific clauses, dates, party names, or case numbers across the entire archive using their document management system. Without OCR, paralegals would need to manually read through boxes of documents for each case - with it, a keyword search returns results in seconds.
Accounts Payable Invoice Processing
An accounting department receives hundreds of vendor invoices as scanned PDFs each month. OCR makes each invoice searchable, allowing the AP team to quickly locate specific invoice numbers, PO references, or payment amounts during reconciliation and audits. The searchable text also enables integration with accounting software that can auto-extract key fields like total amount, due date, and vendor name from the OCR layer.
Academic Research on Historical Documents
A historian digitizing 19th-century newspaper archives needs to search for specific names, dates, and events across thousands of pages. OCR processes each scanned newspaper page, making the entire collection text-searchable. Despite older printing methods reducing accuracy to 85-90% on some pages, the ability to search across the full corpus saves months of manual reading and enables statistical text analysis that would be impossible otherwise.
Government Accessibility Compliance
A federal agency must make its public-facing document library accessible under Section 508. Thousands of scanned PDFs from legacy systems need OCR text layers so screen readers can access the content. After OCR processing, each document can be read aloud by assistive technology like JAWS or NVDA. The agency avoids costly manual transcription by using OCR as the first step, then applying additional accessibility tagging to priority documents.
How It Works
Upload Your Scanned PDF
Drag and drop your scanned PDF or image-based document. A quick test: if you cannot select text with your cursor in a PDF viewer, it is a scanned image and OCR will make it searchable. We accept any scan resolution, though 300 DPI produces the best results.
Choose Language & Settings
Select the primary language of your document for optimal character recognition. Enable 'Enhance Low-Quality Scans' if your document has faded text, uneven lighting, or was scanned below 200 DPI. For mixed digital-and-scanned PDFs, our engine automatically detects which pages need OCR and skips pages that already contain text.
Download Your Searchable PDF
Your processed PDF is visually identical to the original but now contains a full text layer. Search with Ctrl+F, select and copy any text, or upload to document management systems where it becomes fully indexed. File size typically increases by only 1-5% from the added text data.
Expert Tips for OCR Processing
Scan at 300 DPI for Optimal Results
The single biggest factor in OCR accuracy is scan resolution. At 300 DPI, standard 10-12pt text is represented by enough pixels for reliable character recognition (95-99% accuracy). Below 200 DPI, accuracy drops noticeably because fine character details (serifs, stroke crossings, dot placement) are lost to insufficient resolution. Going above 300 DPI to 600 DPI provides diminishing returns on standard text but helps with very small print (6pt or below). If you are scanning specifically for OCR, set your scanner to 300 DPI grayscale - this is the professional standard used by scanning bureaus worldwide.
Use Enhancement for Degraded Documents
Faded thermal receipts, aged paper with yellowing, and photocopies of photocopies all benefit from the 'Enhance Low-Quality Scans' option. This applies adaptive binarization (Sauvola's method), which handles uneven lighting and background variation far better than simple brightness/contrast adjustments. It also removes salt-and-pepper noise that scanners introduce on older documents. If your first OCR attempt produces garbled text, re-processing with enhancement enabled often recovers 10-20% more accuracy.
Always Select the Correct Language
Language selection loads the correct trained model and character set for recognition. Selecting English for a German document means umlauts and eszett will be misrecognized. For documents mixing two languages (e.g., an English contract with French appendices), select the dominant language - the engine will still recognize common Latin characters from the secondary language. For CJK documents, language selection is critical because it determines which character dictionary (thousands of characters) the classifier draws from.
Verify Critical Data After OCR
OCR is highly accurate but not perfect. Always spot-check key data points in processed documents: financial amounts, dates, names, reference numbers, and legal terms. The most common OCR errors involve visually similar characters: 'O' vs '0', 'l' vs '1', 'rn' vs 'm', and 'cl' vs 'd'. In financial documents, a single digit error can matter significantly. For legal documents, verify party names and clause numbers. A 30-second spot check catches the rare errors that automated recognition misses.