Convert scanned documents into searchable PDFs with OCR. Extract text from images instantly. Fast, secure, and free.
Drop your PDF to extract text with OCR
Click to browse or drag & drop
TL;DR — OCR PDF in under 2 minutes
Three steps. Under two minutes. Files never leave your browser.
Click Browse or drag and drop your scanned PDF or image-based PDF. Works on desktop, iPhone, and Android — no size limit for most documents.
Choose one or more languages — English, Chinese (Simplified), French, German, or Portuguese — then click Run OCR. Pages that already have text are skipped automatically.
Download the OCR'd PDF. The visual appearance is unchanged — an invisible searchable text layer is added behind the original page image.
Why PDFcrest
Accurate text recognition, no daily limits, no signup — the fastest way to make scanned PDFs searchable.
PDFcrest uses Tesseract OCR — one of the most accurate open-source OCR engines. Recognises printed text, mixed fonts, tables, and multi-column layouts with high fidelity.
OCR PDF adds a searchable text layer behind the original page image — the visual appearance of your document is completely unchanged. No reflow, no quality loss.
OCR PDF free with no daily limit, no account, and no subscription. Recognise text in as many scanned documents as you need.
Run PDF OCR on iPhone, iPad, Android, or desktop directly in your browser. No app download needed.
Recognises English, Chinese (Simplified), French, German, and Portuguese — select one or several. Pages that already contain text are left untouched with skip-text, so only genuinely image-only pages are rasterized and OCR'd.
All uploads use TLS encryption. Your PDF is processed in an isolated environment and permanently deleted after download.
PDFcrest automatically deskews tilted scans and cleans up image artifacts before recognition, boosting accuracy without any manual editing on your part.
Comparison
| Feature | PDFcrest | Adobe Acrobat Online | SmallPDF / ilovePDF |
|---|---|---|---|
| OCR PDF — Free | ✓ Always free | ✗ Acrobat Pro required | ✗ 2 tasks/day |
| No Signup Required | ✓ Zero signup | ✗ Adobe account | ✗ Email required |
| No Watermarks | ✓ Never | ✓ | ✗ Free adds watermark |
| Invisible Text Layer | ✓ Appearance preserved | ✓ | ~ Varies |
| Works on iPhone | ✓ Mobile-first | ✓ App required | ✓ |
| File Deleted After Download | ✓ Immediately | ~ Varies | ~ 1 hour |
Use Cases
From researchers to office managers — everyone needs to extract text from scanned PDFs.
Make scanned contracts, invoices, and letters searchable and selectable. Find specific clauses or dates in seconds instead of reading page-by-page.
OCR scanned research papers and historical documents to enable text search, copy-paste for citation, and screen reader accessibility.
Run OCR on scanned invoices to extract invoice numbers, dates, and amounts into accounting software. Eliminates manual data entry.
Make scanned legal briefs, contracts, and case files searchable PDFs for case management systems. Find referenced statutes or clauses instantly.
Convert physical form submissions and paper-based compliance documents to searchable PDFs for digital record-keeping and audit trails.
Take a photo of a document and use PDFcrest to OCR PDF on iPhone from your browser. Convert physical text to a digital, searchable format without a scanner app.
Convert historical records and paper archives into searchable digital files. Popular with libraries and museums preserving legacy collections.
Workflow Recipes
OCR is rarely the last step. Here are the tool combinations PDFcrest users chain together most often.
Snapped a photo of a document instead of scanning it? Turn it into a PDF first, then run OCR here.
Adding a text layer increases file size slightly. Compress the result before emailing or uploading it.
Once a scan is searchable, add a descriptive title and keywords so it surfaces in document-management search too.
OCR each scanned chapter or section individually, then combine them into a single searchable document.
Need the recognised text in an editable format instead? Run OCR first, then open the result with PDF to Word to get an editable document.
Technical Detail
When you OCR a PDF, PDFcrest uses Tesseract — one of the most accurate open-source optical character recognition engines — to analyse the image content of each page. The engine detects text regions, recognises individual characters, and outputs a hidden text layer that is overlaid precisely on top of the original page image.
The key advantage of this approach is that the visual appearance of your PDF is completely unchanged. Readers see the original scanned image. But behind it, an invisible text layer makes the content searchable with Ctrl+F, selectable for copy-paste, and accessible to screen readers. This is the same technique used by Adobe Acrobat's OCR feature.
For best results, your scanned PDF should be at 150 DPI or higher and ideally straight (not rotated). PDFcrest automatically handles deskewing for minor rotation. After OCR, you can further compress the PDF to reduce file size or add searchable metadata using PDFcrest's free tool suite.
Under the Hood
No black box — this is the literal request configuration sent to the Tesseract-based OCR engine every time you click Run OCR on this page.
OCR request parameters:
languages = "eng" # one or more of: eng, chi_sim, fra, deu, por (your selection)
ocrType = "skip-text" # OCRs image-only pages, skips pages that already have text
ocrRenderType = "sandwich" # text layer overlaid behind the page image
deskew = true # auto-straightens tilted scans before recognition
clean/cleanFinal = false # skips extra image-cleanup passes
removeImagesAfter= false # keeps original page images intact
sidecar = false # returns one searchable PDF, no separate text file
| Parameter | Why it's set this way |
|---|---|
skip-text | Skips rasterizing and re-OCRing pages that already have a text layer, so only genuinely image-only pages get the (slower) OCR pass — much faster on documents that are partly or fully already text. |
sandwich | Places recognised text in an invisible layer positioned exactly behind the source image, so the page looks identical while becoming searchable and copyable. |
deskew: true | Straightens pages scanned at a slight angle before recognition — a few degrees of tilt can meaningfully reduce character accuracy. |
languages | Set from the language selector above the upload zone. Supports English, Chinese (Simplified), French, German, and Portuguese — pick more than one for mixed-language documents. |
FAQ
Answers to the most common questions about running OCR on PDF files
References & Further Reading
Page last updated: · Written and maintained by the PDFcrest team. The OCR configuration shown above is taken directly from the request this page sends.