How OCR works
OCR PDF uses optical character recognition to detect text inside scanned or image-based PDF pages. It can create a searchable PDF by placing a hidden text layer over the original pages, and it can also export the recognized content as plain text for copying or editing.
In simple terms, OCR reads text from a picture. If your PDF is made from scans or images, the text only looks readable but cannot actually be selected or searched. OCR analyzes each page, recognizes letters and words visually, and turns them into real text that your device understands.
This is different from a typical PDF to text tool. If a PDF already contains selectable text, that tool simply extracts it instantly. OCR is only needed when the PDF has no real text layer and everything is just an image — for example scans, photos, or printed documents saved as PDF.
When to use this tool
OCR is useful when text looks visible on the page, but you cannot actually search, highlight, or copy it from the PDF.
- Turn a scanned paper document into a searchable PDF.
- Recognize text from phone scans saved as PDF.
- Recover text from image-only PDFs that cannot be copied normally.
- Extract readable text from old reports, letters, invoices, or archived documents.
Need to pull text out of a PDF that already has selectable text? Use extract text from a PDF into plain text. Need page images instead of OCR text? Try convert PDF pages into images. Need to process only certain pages first? Use extract selected PDF pages into a new PDF.
Step-by-step: run OCR on a PDF
Making your PDF searchable takes just a few steps:
- Add your PDF. Drag and drop the file into the box above, or click to choose it from your device.
- Choose the OCR language. Use Automatic detection or pick the main document language manually.
- Choose the page scope. Run OCR on all pages or tap individual pages manually.
- Choose the output. Searchable PDF is selected by default, and you can also export a text file if needed.
- Choose text preview visibility. Turn the recognized text preview on only if you want to see it under the pages.
- Run OCR. The tool processes the pages in your browser and creates the result locally.
What the output includes
- Searchable PDF: the page appearance stays the same, while a hidden recognized text layer is added for search, highlight, and copy support in compatible PDF viewers.
- Text file: a plain .txt export of the recognized content for reuse, cleanup, or pasting elsewhere.
- Optional preview: you can show the recognized text preview before saving when you want to review OCR quality.
OCR does not usually recreate the original document layout perfectly as editable text. It is best for recognition, searching, copying, and basic text recovery.
Privacy, limits and how this tool treats your files
FileYoga is built around a simple rule: your files stay with you. OCR runs locally in your browser, so your PDFs are never uploaded to FileYoga servers.
Local-only processing
The OCR happens in your browser on your device. Your PDF is not uploaded, and the output files are generated on your side.
No hidden copies
When you clear the file or close the tab, the tool stops using your PDF and does not save copies on a server.
No artificial limits
No paywalls or quotas. The real limits come from your device speed, browser memory, page count, and scan quality.
No account required
Use the tool without signing up. Open the page, run OCR, save the result, and leave when you are done.
Tips for best results
- Choose the OCR language manually when you already know the main document language.
- High-contrast, straight, clear scans usually produce better OCR than blurry, tilted, or shadowed pages.
- Run OCR only on the pages you need when the PDF is large or your device is slower.
- Use the recognized text preview when accuracy matters before saving the final output.
- If the searchable PDF becomes larger after OCR, compress it afterward.
- Mixed-language documents may need separate runs if one language dominates different page groups.
Troubleshooting
- OCR is slow: large PDFs, high-resolution pages, and many scanned pages take longer because each page is analyzed in your browser.
- Recognition quality is poor: the scan may be blurry, low-resolution, skewed, noisy, or captured in poor lighting.
- Automatic detection picked the wrong language: rerun OCR and choose the main language manually for better accuracy.
- Searchable PDF looks unchanged: that is expected — the visible page usually stays the same while hidden searchable text is added behind it.
- Some words are wrong or missing: decorative fonts, handwriting, tables, stamps, low contrast, and mixed languages can reduce OCR accuracy.
- Error on the PDF: the file may be damaged, encrypted, too complex, or too heavy for the browser — re-save it in a desktop PDF app and try again.
Frequently asked questions
Yes. When you choose searchable PDF output, the tool adds a hidden recognized text layer so supported PDF viewers can search, highlight, and copy text more easily.
Yes. Choose the text-only output mode if you want only a .txt file instead of a searchable PDF.
Not always. Automatic detection is best-effort. For better OCR accuracy, choose the main language manually when you know it.
Yes. Switch the page scope to manual selection and click only the pages you want to process.
Usually yes. Searchable PDF output keeps the original page image visible and adds recognized text behind it instead of redesigning the page.
Sometimes, but accuracy is usually lower. OCR works best on clear printed text. Handwriting, blur, shadows, stamps, and skewed scans can reduce recognition quality.
OCR PDF recognizes text from scanned or image-based pages. PDF to Text is better when the PDF already contains selectable text and you only want to extract it.
No. The OCR runs locally in your browser on your device. Your PDF file is not uploaded to FileYoga servers.