Complete Guide to OCR: How to Extract Text from Images and PDFs
By ScanText Team · 12 min read · 2026-09-22
OCR (optical character recognition) converts images of text into actual, editable text. Instead of retyping a document, you upload a photo, screenshot, or scan, and the OCR engine reads the visible characters for you. This guide covers how OCR works, the different types of OCR tasks, language support including Urdu, Hindi, and Arabic, and how to get the best results.
What OCR does
OCR analyzes pixel patterns in an image, identifies where letters and words appear, and maps those shapes to known characters. The output is machine-readable text you can copy, edit, search, or save as a file.
How OCR works
The OCR engine processes your image in several stages: preprocessing (cleaning up contrast, deskewing, removing noise), character segmentation (isolating individual letters), feature extraction (identifying distinguishing parts of each character), and classification (matching features to known characters). Modern browser-based OCR performs all of this locally in your browser—no uploads required.
Types of OCR tasks
- Image to text — extract plain text from JPG, PNG, WEBP images
- PDF to text — read text-based PDFs directly, or run OCR on scanned PDF pages
- Screenshot to text — copy text from UI screenshots, error messages, chat captures
- Receipt to text — extract merchant, date, totals, and line items from receipt photos
- Handwriting to text — convert neat block handwriting to editable text
- Table to Excel — detect rows and columns in table images, output XLSX
- Image to Word — place OCR text into an editable DOCX document
- Multilingual OCR — extract text in Urdu, Hindi, Arabic, and other scripts
- Image translation — OCR + translate text into another language
Try the image-to-text converter
Multilingual OCR: Urdu, Hindi, Arabic
Standard OCR models are trained primarily on Latin scripts. For languages like Urdu (Nastaliq/Arabic script), Hindi (Devanagari), and Arabic, specialized models are required. ScanText provides dedicated tools for each:
- Urdu Image to Text — extracts Urdu text with RTL display and Unicode preservation
- Hindi Image to Text — reads Devanagari script including conjunct characters and matras
- Arabic Image to Text — extracts Arabic with proper RTL rendering and ligature handling
- Translate Urdu Image — OCR extracts Urdu, then translates to English, Hindi, or Arabic
Each tool uses a language-specific OCR model loaded on demand, so English OCR speed is unaffected.
Image translation: OCR + translate
Image translation adds a step: after OCR extracts the source text, it is translated to your target language. This is useful for signs, menus, documents, and screenshots in foreign languages. ScanText's Image Translator supports English, Spanish, French, German, Portuguese, Italian, and the new Urdu→English/Hindi/Arabic workflow.
Supported image formats
ScanText accepts JPG, JPEG, PNG, and WEBP up to 12 MB (25 MB for some tools). For PDFs, use the PDF to Text or PDF to Word converters. Export other formats (TIFF, HEIC, GIF, SVG) to a supported format first.
How to improve OCR accuracy
- Use sharp, well-lit images with strong contrast between text and background
- Keep text straight — tilted or rotated text reduces accuracy significantly
- Crop tightly around the text area, removing borders and distractions
- Avoid glare, shadows, and motion blur on photographed documents
- For screenshots, capture at native resolution; don't upscale blurry images
- For multilingual OCR, select the correct language before extracting
Common OCR limitations
- Handwriting, cursive, and decorative fonts produce lower accuracy
- Very small text or low-resolution images lose character detail
- Complex layouts (columns, tables, sidebars) may need manual cleanup
- Similar-looking characters (0 vs O, 1 vs l) can be confused
- Urdu Nastaliq and Arabic ligatures may need review
- OCR does not understand context — always verify critical information
Privacy and security
All ScanText OCR tools run entirely in your browser. Images are never uploaded to a server. No account, no tracking, no permanent storage. The extracted text stays in your session until you close the page.
Choosing the right ScanText tool
- General images, screenshots, photos → Image to Text
- Scanned or text-based PDFs → PDF to Text
- Urdu documents, signs, screenshots → Urdu Image to Text
- Hindi/Devanagari text → Hindi Image to Text
- Arabic documents → Arabic Image to Text
- Need translation after OCR → Image Translator or Translate Urdu Image
- Receipts, expenses → Receipt to Text
- Tables to spreadsheets → Image to Excel
- Editable Word document → Image to Word or PDF to Word
- Multiple images at once → Batch Image to Text
Frequently asked questions
- Is OCR free on ScanText? Yes, all tools run in your browser at no cost.
- Do I need to install anything? No, everything works in a modern web browser.
- Is my data saved? No. Processing is local to your browser.
- Can OCR read Urdu/Hindi/Arabic? Yes, dedicated tools use language-specific models.
- What is the difference between OCR and image translation? OCR extracts text; image translation extracts text then translates it to another language.