---
title: "OCR PDF — Make Scanned PDFs Searchable | Compress Pro"
description: "Make scanned PDFs searchable right in your browser — an invisible text layer is added over the original pages. Local Tesseract OCR, zero uploads. Free."
canonical: https://compress-pro.com/ocr-pdf
---

# Make scanned PDFs searchable.

> Scanned PDFs become searchable — all recognized on-device.

Make scanned PDFs searchable entirely in your browser — **every page is recognized on your device and an invisible text layer is laid over the original**. The document looks exactly the same, but suddenly you can select, copy and Ctrl-F it. Nothing is uploaded.

**No uploads · No ads · Free & open source.**

## How it works

1. Drop files anywhere on the page, click to browse, or paste with Ctrl/⌘ + V.
2. Pick a quality or preset — or set an exact target size and let the tool find it.
3. Compress, compare before/after, and download — individually or as a ZIP.

## An invisible layer over your original pages

The pages themselves are never re-rendered or recompressed — the original PDF is kept and only a transparent text layer is added on top, word by word, exactly where each word sits in the scan. File size barely changes and the visual quality cannot degrade. When the goal is a smaller file rather than a searchable one, [Compress PDF](https://compress-pro.com/compress-pdf) is the tool; the two combine well — compress first, then recognize.

## Which PDFs need OCR at all

PDFs born digital — exported from Word, invoices from software, web receipts — already carry a text layer and need nothing. Scans are the ones that don’t: a scanned contract is just photographs of paper until OCR gives it words. Recognition uses the same eight self-hosted [Tesseract languages as the image tool](https://compress-pro.com/image-to-text), and picking the document’s language is what makes accented characters come out right.

## Frequently asked questions

### Does the PDF look different afterwards?

No — the original pages are untouched; the added text layer is invisible. The only change you notice is that selection, copying and search suddenly work.

### How accurate is the recognition?

On clean 300-DPI scans of printed text, very — occasional misreads happen on stamps, tables and low-quality faxes. The layer is invisible either way, so a misread never disfigures the document.

### How long does a big scan take?

Roughly a second or two per page on a modern laptop — an 80-page contract is a coffee-length job. Everything runs locally, so nothing queues behind other people’s files.

### Is it private?

Yes. The document never leaves your browser — nothing is uploaded, and the server only delivers this page. That makes it safe for contracts, invoices, medical records — anything you would not email to a stranger. Want proof? Run one file through, switch your connection off, and run another — it still works.

## Related tools

- [Extract text from images](https://compress-pro.com/image-to-text)
- [Compress PDFs](https://compress-pro.com/compress-pdf)
- [Merge PDF files](https://compress-pro.com/merge-pdf)

---

Part of [Compress Pro](https://compress-pro.com/) — every tool page has a markdown twin at `<page url>.md`. Full tool index: [llms.txt](https://compress-pro.com/llms.txt)