---
id: KB-GL-009
url: https://app.codecontract.io/help/glossary/what-is-ocr
idioma: en
categoria: glosario
subcategoria: documentos
audiencia: usuario
nivel: intermedio
actualizado: 2026-08-13
tambienEn: [es]
relacionados: [KB-DI-004, KB-GL-010]
citadoPor: [KB-GL-020]
---

# What is OCR

_Turning a picture of text into text that can be searched and read._

**Responde a:** what is ocr · optical character recognition · how a scanned pdf is read · search inside scanned documents

**OCR** — Optical character recognition: the technique that looks at the image of a page and recognises which letters and numbers are on it, turning it into text.

A scanned PDF is a photograph of a piece of paper: to a computer, pixels. OCR is what turns those pixels into words, and it is what then allows searching inside it or extracting a date from it.

## Why it sometimes fails

| Original | How well it is recognised |
| --- | --- |
| Computer-generated PDF | Perfectly: the text is already inside |
| 300 dpi scan, straight | Very well |
| Phone photo, in good light | Well |
| Crooked or shadowed photo | Patchy or badly |
| Handwriting | Badly, and that is expected |

> [!WARNING]
> What you cannot read at a glance, OCR cannot either. If you hesitate looking at the document, do not expect it to come out well.

> [!NOTE]
> A PDF that already carries text does not need OCR, which is why it reads perfectly. Asking for PDFs instead of photos is the cheapest way to improve reading.

**Does OCR change my document?**

No. The original is stored as is; the recognised text is kept separately.

**Does it work in other languages?**

Yes, including non-Latin scripts.

**Can misreadings be corrected?**

Yes, and the correction improves reading for that document type.

## Ejemplos

**A company cannot find anything inside its old scans.**

- Checks they were uploaded without reading
- Reprocesses them

→ They become searchable by content, not just by filename.

**A photo of a delivery note does not allow searching by order number.**

- Checks it was processed on upload

→ The number is found without opening the image.

**A skewed, shadowed scan reads badly.**

- Retakes the capture with better light and framing

→ Reading improves without changing anything in the system.

**A handwritten document does not read well.**

- Reviews by hand whatever is flagged as uncertain

→ You correct the little that fails instead of keying it all.

**A PDF already contained text and is processed again.**

- Checks whether the document was already searchable

→ You avoid spending on something that was not needed.

**There are hundreds of unprocessed old scans.**

- Processes first the ones actually consulted

→ Effort concentrates on what somebody will look for.