How to make a scanned PDF searchable

Why you can't search a scanned PDF

A scanner or a phone camera takes a picture of the page. Saved as a PDF, it's still a picture: to a computer there are no words in it, only dots of colour. That's why searching finds nothing, you can't select a sentence, and copying gives you nothing useful.

A quick test: try to select a word with the mouse. If nothing is selected, or the whole page is selected as one picture, the PDF needs OCR. In PDFZyro, a bar also appears when you open a document that looks like a scan, with a Make searchable button.

How to make a scanned PDF searchable in PDFZyro

1. 1Open Make searchable (OCR) on the Home page and choose the scanned PDF from your documents, or upload it. If the scan is already open, click Make searchable in the bar at the top.
2. 2Choose the document's language, or up to three if it mixes languages. English, Spanish, French, German, Italian, Portuguese, Dutch and Russian are available.
3. 3Choose All pages, or Some pages and type them, for example 1-3, 5, 8-.
4. 4Keep Turn sideways pages upright ticked if some pages were scanned the wrong way round.
5. 5Click Make searchable. Recognition runs in the background; you can follow its progress and stop it if you need to.
6. 6Read the summary: how many pages were recognized, the average confidence, and any pages that were hard to read or had no text.
7. 7The searchable PDF is saved as a new version, and the original scan is kept as the previous version. Search, select and copy the text, or download the file.

How to get accurate OCR results

• Scan at 300 DPI. Lower resolutions blur small letters and lead to more mistakes.
• Keep pages straight and flat. A photo taken at an angle, or a page curling towards a book's spine, is harder to read.
• Aim for good contrast: dark text on a light page works best. Avoid shadows when you photograph documents with a phone.
• Choose the right language. OCR uses the language's letters and words to decide what it's reading, so the wrong one gives more mistakes and can lose accents.
• Check the pages PDFZyro flags as hard to read. OCR is made for printed and typed text, so handwriting is usually not recognized well.

What you can do with a searchable PDF

• Find any word in the document, or from the search bar across all your documents in PDFZyro.
• Select and copy text into an email, a spreadsheet or another document.
• Convert the scan to an editable document with PDF to Word or PDF to Excel.
• Redact by search: Search & redact can find names, email addresses or numbers in the scan once its text is recognized.
• Compare it with another version of the document word by word.
• Fill in a scanned form more easily: PDFZyro can read labels such as Name: and suggest places to type.

Other ways to make a scanned PDF searchable

• Scanner software: many scanners and scanning apps can save a searchable PDF directly. Look for an OCR or searchable PDF setting before you scan.
• Adobe Acrobat: the paid version can recognize text in scanned PDFs. The free Acrobat Reader can't.
• Google Drive: opening a scanned PDF with Google Docs copies its text into a new document. You get a Doc rather than a searchable PDF, and the layout is usually lost.
• Live Text on a Mac or iPhone: recent versions let you select text in pictures, which is handy for copying a line, but nothing is saved in the PDF, so it still can't be searched.

Keeping scanned documents private

Scans are often of personal papers: ID documents, medical letters, bank statements, signed contracts. Before you use an online OCR service, check where your files go and how long they're kept.

In PDFZyro, text recognition runs on PDFZyro's own servers, so your scans aren't sent to an outside OCR service. Stored documents are encrypted and stay private to your account unless you share them, and you can delete them whenever you like.