# PDF, DOCX and OCR detection

Source: https://iachecker.com/docs/document-detection
Status: Available now
Last verified: 2026-08-08

The Document Reader converts supported files into readable text before analysis. It prefers fast native extraction and uses OCR for scanned or layout-heavy material.

## Extraction pipeline

1. **Validate**: The web route verifies type, size and access before forwarding the file.
2. **Extract natively**: PDF text layers, DOCX structure and plain text formats use native readers first.
3. **Apply OCR when needed**: Scans, images and complex layouts can use Docling to recover readable text.
4. **Return normalized text**: The detector receives plain text plus extraction metadata, not a visual imitation of the page.

## Limits and access

- Document upload is available from Plus.
- The maximum upload size is 20 MB.
- The extraction service returns up to 120,000 characters before the selected tool applies its own limit.
- OCR jobs use short-lived in-memory state and expire after approximately 15 minutes.

## Check extraction quality

Review the extracted text before interpreting a detection score. Missing columns, scrambled reading order or OCR substitutions change the linguistic structure available to the detector.

> **A clean export helps**
>
> If a scanned PDF is difficult to read, export it at a higher resolution or upload the original DOCX when you control the source.

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- [IA Checker documentation](https://iachecker.com/docs)
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