What is OCR?

What OCR does

A scan or photo of a document is an image — there's no text data behind the pixels. OCR analyzes that image, recognizes the letters and words, and outputs real text that software can search, select, and read aloud.

How OCR works

The engine finds regions of text, separates them into lines and characters, and matches the shapes to a language model to decide which characters they are. The recognized text is then written back — in a searchable PDF, as an invisible layer aligned to the printed words.

When you need it

Any time you want to search, copy, or extract text from a scan, photo, or fax — making a scanned contract searchable, pulling figures out of a scanned report, or feeding a scan into PDF to Text or PDF to Word.

What affects accuracy

Higher-resolution, high-contrast, straight scans recognize best. Picking the correct language improves results, and unusual fonts or handwriting are harder — handwriting in particular is unreliable.

OCR in PDFER

The OCR PDF tool recognizes text on your device and adds a selectable layer to the scan. The first use of a language downloads its model once from the same origin, then works offline — and your document is never uploaded.

Frequently asked

What does OCR stand for?

Optical character recognition — technology that converts an image of text into real, machine-readable characters.

Is OCR always 100% accurate?

No. Clean, high-contrast scans recognize very well, but low-quality images, unusual fonts, and especially handwriting can produce errors worth proofreading.

What languages can OCR recognize?

PDFER offers several (including English, Spanish, French, German, Italian, Portuguese, and Dutch). Picking the document's language improves accuracy.

Does OCR upload my document?

Not in PDFER — recognition runs entirely in your browser, so the file never leaves your device.