SkanHow to make a scanned PDF searchable
A scanned PDF is a picture of each page, so you can’t search it or copy text from it. Text recognition (OCR) reads the picture and adds an invisible layer of text on top, lined up with the words on the page. You can do it in Adobe Acrobat Pro, with an online OCR tool, which means uploading the file, or on your iPhone with a scanner app such as Skan, which keeps the file on the phone.
First, check whether the PDF already has text
Open the PDF on a computer and search for a word you can see on the page (Cmd-F on a Mac, Ctrl-F on Windows). If the word is found, or you can select a single word with the mouse, the PDF already has text. If nothing is found, the pages are only images and need OCR.
On iPhone, without uploading
- Save the PDF in the Files app, for example from Mail with Save to Files.
- Open Skan, tap the + button and choose Import from Files.
- Pick the PDF and check its pages.
- Tap Save PDF. Skan reads the text on every page and saves a new PDF with a text layer.
- Open the document and tap Share PDF to save it back to Files or send it on.
The new PDF can be searched and copied in any PDF reader, and the pages still look like the scan. Skan reads Danish and English, plus your iPhone’s language if it’s Japanese, German, French, Spanish, Korean, Italian, Portuguese, Dutch, Swedish or Norwegian (Danish, Dutch, Swedish and Norwegian need iOS 26 or later). It works in Airplane Mode, has no account and no server, and its App Store listing says “Data Not Collected”. For new paper, scan it straight to a searchable PDF instead: here’s how to scan documents on iPhone.
In Adobe Acrobat
Acrobat on a computer can recognise text in a scanned PDF; Adobe’s own guide is How to make a PDF file searchable. The tool is part of the paid Acrobat plans, not the free Acrobat Reader. The file stays on your computer unless you save it to Adobe’s cloud.
With an online OCR tool
Sites such as iLovePDF and Smallpdf, and Adobe’s online tools, offer OCR in the browser. You upload the PDF, their servers read it, and you download the result. That’s fine for a menu or a public brochure. For a contract, a payslip, a medical letter or a copy of your passport, think twice: the file leaves your device, and you rely on the site to delete it.