StackPDFStackPDF

OCR PDF

Turn scanned PDFs into searchable, selectable text.

How it works

  1. 1Drop a scanned or image-only PDF into the workspace.
  2. 2Leave language on Auto-detect, or pick a specific language pack.
  3. 3Optionally set a from–to page range for long documents.
  4. 4Run OCR and watch progress (you can cancel a long job).
  5. 5Review recognized text and confidence boxes on sample pages.
  6. 6Download the searchable PDF and/or plain-text export.

About

Run offline OCR (Tesseract) on scanned or image-only PDFs in your browser. Language is auto-detected from the first page (or force a language). Optional page ranges, searchable PDF plus plain text, and per-page confidence boxes.

Phone captures and flatbed scans look fine to the eye but cannot be searched or selected until a text layer exists. StackPDF recognizes pages on your device, shows accuracy feedback, and lets you download a searchable PDF or a .txt extract.

No cloud OCR API and no per-page billing: good for IDs, medical paperwork, and legal scans that must not leave the machine.

Common use cases

  • Make a phone-scanned contract searchable before filing
  • OCR receipts and invoices for text export or bookkeeping
  • Add a text layer to archive scans so find-in-document works
  • Prepare a scan for PDF to Word or PDF to Excel
  • Process multilingual scans with auto language detection

Why scanned PDFs need OCR

A scan is a picture of pages. Without OCR, search fails, copy/paste fails, and downstream tools like PDF to Word have nothing to extract. OCR adds a text layer aligned to the page images so the file behaves like a normal document for search and selection.

Running that step in the browser avoids sending passport scans or medical forms to a remote recognition API.

Languages, ranges, and feedback

Auto-detect picks a language pack from the first page; override it when you already know the language. Page ranges save time on long binders when only a section matters.

Progress, cancel, and confidence overlays make long jobs manageable on a laptop. Very large files are still limited by device CPU and memory — that is the tradeoff for staying offline.

When cloud OCR might still make sense

Server fleets processing millions of pages, specialized handwriting models, or tightly integrated enterprise capture systems may justify a cloud OCR product.

For interactive, privacy-sensitive scans on one computer, local Tesseract is the practical default: free of per-page billing and free of an upload step.

FAQ

Related guides

Related tools

PDF to Word

Rebuild a .docx from extracted text — fine for notes, not a layout clone.

Images to PDF

Combine JPG, PNG, and WebP images into one PDF.

PDF to HTML

Rebuild semantic HTML from extracted text — not a visual clone.