STRAIGHTEN THE SCAN BEFORE YOU READ IT.
Straighten crooked scanned PDF pages.
Detect small scan angles, review the proposed correction and fine-tune individual pages before rebuilding the scan - with a direct next step into OCR when you need searchable text.
- 1. Choose
- 2. Prepare
- 3. Process
- 4. Review & export
Choose a scanned PDFDrop a file here or browse. Files stay on this device — nothing is uploaded to run this tool.
Deskew PDF runs locally in this browser tab. Known limits: Deskew re-renders scanned pages
What this tool does and does not change
- Deskew re-renders scanned pages
Questions about Deskew PDF
- What is the difference between Deskew PDF and Rotate PDF?
- Rotate PDF changes page orientation in 90-degree steps and can preserve normal PDF content. Deskew corrects small angles in scanned page images, such as 1.8 degrees clockwise, and usually involves raster image transformation.
- How does automatic deskew work?
- The tool analyzes visual features such as text baselines or strong horizontal/vertical structures and estimates a correction angle. The exact algorithm should expose confidence so uncertain pages are not modified automatically.
- Can I adjust the angle manually?
- Yes. Every proposed correction should be reviewable, with a small manual fine-adjustment control for pages where automatic detection is slightly wrong.
- Will deskew improve OCR accuracy?
- Often, especially when text lines are clearly tilted. It is not a guarantee, but straightening the scan before recognition can make character segmentation easier. PDF Atelier should offer OCR as the natural next step.
- Will Deskew PDF reduce image quality?
- Any raster transform can introduce some resampling. The tool should use a high-quality transform, preserve sensible resolution and avoid repeatedly re-encoding the same page across chained tools.
- Can I deskew only selected pages?
- Yes. Page ranges/selection are important because some pages may already be straight or may contain photos/diagrams where automatic angle detection is unreliable.
- Should I use Deskew on a digital text PDF?
- Usually no. If the PDF contains real text/vector content and only appears visually unusual, rasterizing it would unnecessarily destroy useful semantics. The tool should detect text-native pages and warn or recommend Rotate/Crop instead.
- Is deskew processing local?
- When marked Local, angle detection, page rendering and transformation run in browser workers. Page images should not be uploaded to a scan-cleanup service.
Related tasks
- OCR PDF recognize text after straightening the scan.
- Rotate PDF fix pages that are sideways or upside down.
- Crop PDF trim unwanted scanner borders.
- Compress PDF reduce the size of cleaned image-heavy scans.