Scanned archives
Make old scanned records searchable without manually retyping every page.
PDF & OCR Tools
OCR PDF & Make PDF Searchable
Turn scanned PDF pages into searchable documents while preserving the visual page. OCR runs in your browser and the result can be verified before download.
Current searchable-text layer: English OCR. Multilingual OCR extraction remains available in the existing Multilingual Document OCR tool.
OCR is machine-generated and should be verified for important names, numbers and legal or financial fields.
PDF authority guide
Make scanned PDF pages searchable without retyping them
Searchable PDF OCR recognises text from scanned page images and adds a searchable text layer while preserving the visual scan. OCR is an interpretation, not a guarantee: names, identifiers, totals and similar characters must be verified against the page image before the result is used operationally.
How to use this tool
- 1
Upload a scanned or image-based PDF.
- 2
Choose the document language and start OCR.
- 3
Review recognised text and low-confidence areas.
- 4
Create the searchable PDF and test search/select behaviour.
Real-world value
When this PDF tool is useful
Document discovery
Use browser search to find names, references or clauses in scans.
Accessibility workflow
Add machine-readable text that can support downstream document processing.
Preparation for conversion
OCR a scan before PDF-to-Word or data extraction.
Avoid these issues
Common mistakes
- !Treating OCR output as authoritative without review
- !Using the wrong OCR language
- !Processing blurred or rotated scans without correction
- !Assuming handwriting will recognise like printed text
Better results
Professional tips
- ✓Use the correct language for the document
- ✓Rotate and improve poor scans before OCR
- ✓Verify identifiers and financial values character by character
- ✓Test Ctrl+F in the downloaded PDF
Engineer's checklist
Prepare, process and verify
Before processing
- •Choose the correct OCR language.
- •Rotate sideways pages and use the clearest available scan.
- •Identify critical values that must be manually verified after recognition.
After download
- •Search for several known words in the downloaded PDF.
- •Compare names, identifiers and totals with the visible scan.
- •Inspect pages with low recognition confidence.
Technical considerations
- •OCR output is probabilistic and should not be treated as authoritative data without review.
- •Similar glyphs such as 0/O and 1/I are common recognition errors.
- •A searchable PDF normally combines the original page image with a machine-readable text layer.
Troubleshooting
What to check when processing fails
The PDF will not open
Confirm that the file is a valid PDF and is not damaged or protected by an unsupported security setting.
Processing stops or the tab becomes slow
Try a smaller document, split the source into sections, or use a device with more available memory.
The output looks different
Review fonts, transparency, annotations and complex forms; these features can behave differently after a document is rebuilt.
PDF architecture
Understand what changes inside a PDF workflow
A PDF page can combine selectable text, embedded fonts, vector paths, bitmap images, annotations, links and form controls. A PDF utility may preserve those objects, rearrange them, compress their resources or render the page into pixels. Knowing which operation is taking place helps you choose the right tool and verify the result correctly.
Page objects
Text, vectors, images and annotations can remain separate objects until a page is rasterised.
Fonts and text layers
Selectable text depends on embedded fonts, character maps and the original document structure.
Resolution
When a page becomes an image, DPI or render scale controls how much detail is available for small text and diagrams.
Document security
Encryption, permissions and digital signatures can restrict processing or become invalid after modification.
What the operation can change
- Page reordering and merging usually preserve the original page objects.
- Compression may resample images or remove redundant resources.
- Image conversion flattens text, links, forms and vectors into pixels.
- Editing a signed PDF can invalidate its digital signature.
Domain-specific verification
- Check page count, order, orientation and page dimensions.
- Zoom into small text, signatures, tables and engineering lines.
- Confirm whether search, links, forms and bookmarks still work when required.
- Keep the original document when legal, archival or print fidelity matters.
Continue your workflow
Related PDF actions
Questions answered
Frequently asked questions
What is a searchable PDF?+
It keeps the visible scanned page while adding text that a PDF reader can search or select.
Does OCR change the page image?+
The goal is to retain the visible scan and add a machine-readable text layer rather than redesign the page.
Is OCR always accurate?+
No. Scan quality, language, fonts and layout affect recognition, so important values must be verified.
Can it recognise multiple languages?+
Use the supported language selection appropriate for the document; mixed-language pages can require extra review.
Why does 0 become O or 1 become I?+
These characters can look nearly identical in scans, which is a common OCR ambiguity.
Can I OCR a PDF that already has text?+
Usually OCR is most useful for image-only pages. Existing selectable text should be preserved when possible rather than recognised again.
Do I need to install any software?+
No. The tool runs in a modern web browser, so there is no desktop application to install.
Does it work on mobile devices?+
Yes, although large documents are usually faster to process on a desktop or laptop with more available memory.
Will the original PDF be changed?+
No. Your original file remains unchanged. The tool creates a new output file for you to download.
Why can a large PDF take longer?+
PDF processing uses your device memory and processor. Scanned, image-heavy and very long documents naturally require more work.
Can password-protected PDFs be processed?+
A locked PDF may need to be unlocked with the correct password before browser-based processing can read or modify it.
Which browsers are supported?+
Current versions of Chrome, Edge, Firefox and Safari provide the best experience.
Explore the complete PDF toolkit
Use FormatForge PDF tools together to organise, clean, convert and optimise documents without installing specialist desktop software.
OCR quality guide
Use searchable PDF OCR for scanned pages that need discovery and downstream processing
OCR adds machine-readable text to page images, but recognised text must be treated as interpreted data. Verify names, identifiers, dates and totals against the visible scan.
Choose this tool when
- ✓Ctrl+F cannot find visible words in a scanned PDF.
- ✓An archive needs basic searchability.
- ✓A scan must feed a later PDF-to-Word workflow.
Use another workflow when
- →The PDF already contains accurate selectable text.
- →The scan is too blurred or incomplete to verify.
- →Handwriting accuracy is critical and cannot be manually reviewed.
Worked example
Example: scanned archive
- Starting point
- A 40-page scanned report with no selectable text
- Useful result
- A visually similar PDF with a searchable text layer, followed by checks of important identifiers.
Verification checklist
□ Correct OCR language
□ Page orientation
□ Critical values verified
□ Ctrl+F works
Important limitations
- OCR can confuse visually similar characters.
- Poor scans reduce accuracy.
- Complex layouts and handwriting require extra review.