# OCR for PDFs and Images: How to Get Accurate Text > Optical character recognition reads the shapes of letters in an image or a scanned page and turns them into real, selectable text. - Page: https://acepdfmd.com/guides/ocr-guide/ - Updated: 2026-09-14 - Runs at: https://acepdfmd.com (Uploaded files are deleted within 60 minutes. No signup for light use.) - Also in 29 languages: https://acepdfmd.com//guides/ocr-guide/ ## What OCR Actually Does A scanned page, or a photo of a document, is just an image, a grid of pixels with no notion of letters or words. OCR analyzes that grid, recognizes character shapes, and outputs the text it finds along with the position of each recognized word on the page. ## Searchable PDF vs Extracted Text [OCR PDF](https://acepdfmd.com/tool/ocr-pdf/) adds an invisible, searchable text layer over the original page image, so the page still looks exactly like the scan but the text underneath is selectable and searchable in any PDF viewer. [Image to Text](https://acepdfmd.com/tool/image-to-text/) instead extracts the recognized text on its own, with no page image involved, for when you just want the words. ## Languages and Auto-Detection Recognition supports 95 or more languages. Language can be auto-detected page by page, which is convenient for mixed documents, or you can pick one or more languages manually when you know exactly what the document contains. Manual selection tends to be more accurate than auto-detection for short or unusual documents where there is not enough text to detect language reliably. ## Scan Quality Tips Pages are read at 300 dpi, which is a good baseline for standard printed text. A few habits make a real difference to accuracy: - Keep the page straight; skewed text reduces recognition accuracy noticeably. - Use even lighting and avoid shadows across the page, since low contrast confuses character shapes. - Scan at 300 dpi or higher rather than relying on a low-resolution phone photo. - Flatten curled or folded pages before scanning where possible. ## Mixed-Language Documents For a page that switches between two or three languages, select all the relevant languages manually rather than relying on auto-detection, which works per page and may miss a language that only appears in a small section of that page. ## Tables and Forms OCR recognizes the text inside table cells and form fields, but it does not always preserve the original grid structure perfectly, especially with thin borders or unusual layouts. Check numeric tables carefully, since a misread digit is easy to miss visually. ## Handwriting Limits Recognition accuracy drops sharply on handwriting, and it drops further with small print, decorative fonts, low contrast and skewed pages. Neat, printed block letters fare better than cursive handwriting, but no OCR tool here is a reliable replacement for a human transcription of handwritten notes. ## Checking Results Always spot-check OCR output against the original, particularly numbers, names and any text in small print. A quick skim of a converted page catches most recognition errors before they cause a downstream problem. ## Choosing the Right Tool Use [OCR PDF](https://acepdfmd.com/tool/ocr-pdf/) when the final file needs to keep looking like the original scan but become searchable. Use [Image to Text](https://acepdfmd.com/tool/image-to-text/) when you only need the recognized words, with no page image. Use [Scan to Markdown](https://acepdfmd.com/tool/scan-to-markdown/) when the scanned document has structure, headings, lists or tables, worth preserving as Markdown, as covered in the [PDF to Markdown guide](https://acepdfmd.com/guides/pdf-to-markdown-guide/). Use [PDF to Word](https://acepdfmd.com/tool/pdf-to-word/) when the end goal is an editable document rather than plain text. Whichever tool you pick, a quick manual review of the first page against the output remains the fastest way to confirm the settings you chose were the right ones for that particular document. ## Tools mentioned in this guide - [OCR PDF](https://acepdfmd.com/tool/ocr-pdf/): Make scanned PDFs searchable by adding a text layer. - [Image to Text (OCR)](https://acepdfmd.com/tool/image-to-text/): Extract text from images using OCR. Supports 95+ languages. - [Scan to Markdown](https://acepdfmd.com/tool/scan-to-markdown/): Turn photographed pages into clean, searchable Markdown text. The same deskew and shadow-removal cleanup as Scan to PDF, then OCR extracts the text into a .md file, page by page. - [PDF to Word](https://acepdfmd.com/tool/pdf-to-word/): Convert PDF into an editable DOCX. ## More guides - [Markdown Cheat Sheet: Syntax Reference with Examples](https://acepdfmd.com/guides/markdown-cheat-sheet/) - [PDF Page Sizes and Dimensions: A4, Letter, Legal and More](https://acepdfmd.com/guides/pdf-page-sizes/) - [How PDF Compression Works and Why Some Files Barely Shrink](https://acepdfmd.com/guides/pdf-compression-guide/) - [PDF to Markdown: How It Works and How to Use It for AI](https://acepdfmd.com/guides/pdf-to-markdown-guide/) - [Is It Safe to Upload a PDF Online? A Privacy Guide](https://acepdfmd.com/guides/privacy-guide/) - [Open and Convert iWork Files (Pages, Numbers, Keynote) Without a Mac](https://acepdfmd.com/guides/iwork-guide/) - [JSON Tools Guide: Convert Documents and Data to JSON and Back](https://acepdfmd.com/guides/json-guide/)