Run OCR on a scanned PDF entirely in your browser and download a searchable copy. An invisible text layer is added over the original pages, so Ctrl+F, selection, and copy/paste work — nothing is uploaded.
On-Device OCR (Tesseract WASM) Invisible Text Layer Original Pages Preserved 8 Languages
Last updated
OCR PDF — Make PDF Searchable is a free, browser-based tool
from UseToolSuite's
Document & PDF Tools collection.
All processing happens locally on your device — your data is never uploaded to any server.
Use the tool below, then scroll down for detailed documentation, frequently asked questions, and related resources.
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Drop a scanned PDF here or click to select
Make it searchable with OCR — the file never leaves your device
100% private OCR Ctrl+F works after Original pages kept
The recognition model (~15 MB) downloads once on first use and is cached by your browser. Your document itself is never uploaded.
Pages
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Words found
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Output size
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Visual quality
Unchanged
Extracted text
About OCR PDF
A scanned PDF is just photographs of pages — you can't search it, select text, or copy a paragraph out of it. This tool fixes that by running optical character recognition (OCR) on every page and writing the recognized words back into the file as an invisible text layer, positioned exactly over the printed words. The visible document doesn't change at all — your original pages are copied intact, not re-rendered — but Ctrl+F, text selection, and copy/paste work afterward, and the content becomes indexable. Unlike virtually every other online OCR service, recognition runs entirely in your browser with Tesseract compiled to WebAssembly: the scan — often a contract, medical record, or ID — is never uploaded.
How to Make a Scanned PDF Searchable
Drop in the scanned PDF — it stays on your device.
Pick the document's language — the matching recognition model loads once and is cached.
Run recognition — each page is processed locally; a progress bar tracks it.
Download — the searchable PDF looks identical, and the full extracted text is also available to copy.
What affects accuracy
Scan quality is the biggest factor — clean, straight, 200+ DPI scans of printed text recognize very accurately; skewed, low-resolution, or noisy scans degrade results.
Pick the right language — the model is language-specific; running a Turkish document through the English model will mangle accented characters.
Handwriting is out of scope — OCR engines are built for printed text; handwritten notes will mostly be missed.
If the scan is sideways, fix it first with Rotate PDF — OCR accuracy drops sharply on rotated pages.
To extract text from a single image rather than a PDF, use the Image OCR tool.
Why the text layer is invisible — and why that’s the right design
A searchable scan has two layers: the original page image you see, and machine-readable text positioned at the exact coordinates of each printed word underneath. The text is drawn with zero opacity, so it never alters the document’s appearance — a pixel-perfect scan of a signed contract stays pixel-perfect. But viewers search, select, and copy against that hidden layer, and indexing systems can read it. This is the same architecture commercial OCR software (Adobe Acrobat, ABBYY) produces, because it preserves the scan as legal evidence of the original while making it usable as data.
The alternative — replacing the image with recognized text — would be destructive: OCR is never 100% accurate, and every recognition error would permanently corrupt the document. The invisible-layer approach means errors only affect search quality, never the document itself.
The privacy angle is bigger here than for most tools
Think about what people OCR: signed contracts, court filings, medical records, old IDs, financial statements — the paper trail of their lives. Uploading those to a cloud OCR service means the most sensitive documents you own sit on a third-party server during processing. Running the recognizer in your browser — Tesseract compiled to WebAssembly, with the language model cached locally — removes that exposure entirely: the only thing downloaded is the public model, and nothing about your document goes the other way. You can verify it live in the Network tab while a recognition runs. For a single photographed page rather than a PDF, the Image OCR tool does the same job; to get plain text out of an already-digital PDF, PDF to Text is instant and needs no recognition at all.
How to Use This Tool
1
Upload the scanned PDF
Drag and drop the file — it stays on your device.
2
Pick the document language
The matching recognition model (~15 MB) downloads once and is cached by the browser.
3
Run recognition
Each page is rendered and recognized locally; a progress bar tracks the pages.
4
Download the searchable PDF
It looks identical to the original, but search, selection, and copy now work. The extracted plain text is also shown for copying.
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Essential terms and definitions related to OCR PDF — Make PDF Searchable.
Searchable PDF (image + text layer)
A PDF where the visible content is the original scanned image and an invisible, machine-readable text layer sits at the matching coordinates underneath. Viewers search and select against the hidden layer while displaying the untouched scan — the standard output format of OCR software.
OCR (Optical Character Recognition)
The process of detecting and converting text in an image into machine-readable characters. Modern engines like Tesseract use neural networks trained on printed text and report each recognized word with its position and a confidence score.
Frequently Asked Questions
How is this different from other online OCR tools?
The recognition itself runs in your browser using Tesseract compiled to WebAssembly — your document is never uploaded to a server. Practically every other online OCR service sends the file to their backend for processing. Since scanned PDFs are often contracts, medical records, or IDs, keeping recognition on-device removes the risk of the document sitting on someone else's infrastructure.
Does OCR change how my PDF looks?
No. The original pages are copied into the output untouched — they are not re-rendered or recompressed. The recognized words are added as an invisible (fully transparent) text layer positioned over the printed words, which is the same technique professional OCR software uses. Visually the file is identical; functionally, Ctrl+F and text selection now work.
How accurate is the text recognition?
On clean, straight scans of printed text at reasonable resolution, accuracy is very high. It degrades with skewed pages, low-resolution or noisy scans, decorative fonts, and complex multi-column layouts. Handwriting is largely out of scope — OCR engines are built for printed text. Choosing the correct document language matters a lot, since each model is language-specific.
Why is the first run slower than later ones?
On first use the OCR engine and the language model (~15 MB) are downloaded and cached by your browser. Subsequent runs skip that download and start recognizing immediately. The recognition itself takes roughly one to a few seconds per page depending on your device and scan resolution.
How do I check whether a PDF already has a text layer before OCR-ing it?
Open the PDF in any viewer and try to select a few words with your mouse, or press Ctrl+F and search for a word you can see on the page. If selection works and the search finds it, the file already has a digital text layer and doesn't need OCR — running OCR anyway just wastes time. If the cursor drags a rectangle instead of selecting words and search finds nothing, it's a pure scan and OCR is exactly what it needs.
What scan settings give the best OCR results?
Scan at 300 DPI in grayscale or black-and-white with the page as straight as possible — those three factors dominate accuracy. Below 150 DPI, characters lose the detail the recognizer needs; above 300 DPI adds little except processing time. Avoid photographing documents at an angle with a phone if you can; if a phone photo is all you have, shoot straight-on in even light. Fix any rotation before recognition, since OCR accuracy collapses on sideways text.
Troubleshooting & Technical Tips
Common errors developers encounter and how to resolve them.
Recognized text is garbled or accented characters are wrong
Check the language selection — running a document through the wrong language model mangles diacritics and unusual characters. If the scan is rotated or skewed, fix the orientation first with the Rotate PDF tool; OCR accuracy drops sharply on rotated pages.
Very few words were found on a page that clearly has text
The page may be extremely low resolution, very noisy, or handwritten. Re-scan at 200-300 DPI if possible. Pages that already contain a digital text layer don't need OCR at all — try selecting text in your viewer first.
The process is slow on a large document
OCR is compute-heavy: every page is rendered at ~200 DPI and run through a neural recognizer on your own CPU. A 50-page scan can take a few minutes. The trade-off is privacy — nothing leaves your machine. Keep the tab focused for best speed.
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