Make a scanned PDF searchable with OCR
Recognize the English text in scanned pages and add it as an invisible layer, so you can search, select and copy it. The pages themselves are not changed.
Runs on your device · 0 bytes uploaded
How to oCR PDF
- Add one scanned PDF.
- Click “Recognize text” and wait while each page is read.
- Download the searchable PDF.
Private by design — and you can check
Your files are never uploaded, because there is nowhere to upload them to.
- No upload step existsFiles are read and written inside this browser tab. There is no server that could receive them.
- The browser enforces itThis page’s Content Security Policy only allows connections back to this site, which serves nothing but the app itself.
- See for yourselfOpen developer tools, watch the Network tab and run a job: no request carries your document.
- Open sourceEvery line is on GitHub, built on qpdf, pdf.js and pdf-lib.
Frequently asked questions
Are my files uploaded anywhere?
No. ZapDoc does the work inside your browser tab, using open-source engines compiled to WebAssembly and JavaScript. Your file is read from your device, processed locally, and the result is saved straight back to your device. You can check this yourself: open your browser’s developer tools, go to the Network tab, and run a job — no request carries your file.
Which languages are supported?
English. The recognition engine (Tesseract) and its English language data are downloaded to your browser once, the first time you use an OCR tool — about a few megabytes.
Does OCR change how my pages look?
No. The scanned pages are kept exactly as they are; the recognized text is added as an invisible layer on top.
Is ZapDoc free?
Yes. There is no sign-up, no watermark and no daily limit. ZapDoc is open source under the MIT license.
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