How to Scan Documents With Your Phone and Convert to Searchable PDF
You don't own a scanner. You need to digitise a signed contract, a handwritten letter, medical records, or a stack of receipts. Your phone's camera takes a perfectly readable photo of each page — but a photo of a document isn't the same as a scan. A proper scan is a PDF with selectable, searchable text. Here's how to get there.
The three-step workflow
Step 1: Photograph. Lay the document on a flat, contrasting surface (a dark desk for white paper). Make sure the lighting is even — avoid shadows from your hand or phone. Align the camera directly above the page, not at an angle. Take one photo per page.
Step 2: Convert to PDF. Open the document converter in your phone's browser. Upload all the page photos. Convert to PDF. You now have a multi-page PDF — but the text isn't selectable yet. It's just images in a PDF wrapper.
Step 3: OCR. Run the PDF through the OCR tool to extract the text. The result is selectable, copyable, searchable text. You can now Ctrl+F through a scanned contract, copy an address from a handwritten note, or search through a stack of receipts for a specific amount.
Photography tips for better scans
- Lighting: natural daylight or overhead office lighting. Avoid desk lamps that create harsh shadows on one side. No flash — it creates glare on glossy paper.
- Angle: directly overhead, perpendicular to the page. Angled shots create trapezoid distortion that makes text harder to OCR.
- Flatness: press the document flat if it's curled. For books, open them fully against a flat surface. Curved pages produce curved text that OCR handles poorly.
- Resolution: your phone's default resolution (12 MP or higher) is plenty. Don't zoom in or crop in-camera — capture the full page and crop later if needed.
- Contrast: dark text on white paper is ideal. If the document is on coloured paper or has faded text, converting to black and white after photographing can improve OCR accuracy.
Native scanning apps
iPhone has a built-in scanner in Notes (tap +, Scan Documents). Google Drive has one too (tap +, Scan). Both automatically detect page edges, correct perspective, and enhance contrast. They produce better scans than a raw photo. Use them for the capture step, then continue with the conversion and OCR steps above for a searchable result.
When OCR accuracy matters
OCR works by recognising letter shapes in images. Accuracy depends on the source quality:
- Printed text, clear photo: 95-99% accuracy. Virtually error-free for modern printed documents.
- Printed text, poor photo (blurry, angled, shadowed): 80-90% accuracy. Readable but expect a few errors per page.
- Handwritten text: 60-85% accuracy depending on handwriting legibility. Clean, printed-style handwriting does better than cursive.
- Faded or damaged documents: variable. Increasing contrast before OCR helps significantly.
For critical documents (legal, medical, financial), always proofread the OCR output. For bulk filing (receipts, old correspondence), the occasional error in a search index is acceptable.
File size management
Phone photos are large — 3-5 MB each. A 10-page scanned document can easily be 30-50 MB as a PDF. That's too large for most email attachments and upload portals. After converting to PDF, run it through the PDF compressor to bring it under the required limit. A 30 MB scanned PDF typically compresses to 2-5 MB with minimal visible quality loss.
Bottom line
Your phone is a scanner. Photograph the pages, convert to PDF, run OCR for searchable text. The result is a proper digital document you can search, select text from, and file. Total time for a 5-page document: about 3 minutes.
Start scanning
Convert photos to PDF, then extract text with OCR. Free, works on any phone.