A scanned document is a stack of photographs as far as your computer is concerned — you can't search it, select from it, or have a screen reader read it aloud. OCR fixes that by recognising the text and storing it alongside the image.
Free OCR is unusually restricted elsewhere: iLovePDF doesn't offer it on the free tier at all, and Sejda caps it at ten pages. Running it in the browser means neither cap makes sense, and your scans — which are frequently identity documents and medical records — stay on your device.
The recognised text is added as an invisible layer on top of the original scan, so the document looks exactly the same and the image is never re-encoded.
Type into real form fields, or anywhere on a flat form.
Draw, type, or upload a signature and place it on any page.
Number the pages, with control over position and format.
Add DRAFT, CONFIDENTIAL or a logo across the pages.
Cut away white margins or crop pages down visually.
Combine files into one PDF and set the order before you merge.
Break a document into separate files by range or interval.
Drag pages into a new order, rotate or drop the ones you don't need.
Turn sideways or upside-down pages the right way up.
Pick pages to drop, visually or by range.
Keep only the pages you want as a separate file.