When this tool is useful
Straightening modestly tilted receipts, forms, notes, and text-heavy scans before reading, archiving, or placing them in a PDF.
How local processing works
Automatic mode evaluates bounded candidate rotations from sampled luminance structure and chooses the strongest alignment score; manual mode uses the entered angle. The image is rotated onto a new flattened canvas.
How to use it
- Prepare and preserve the source: Keep an unchanged source, choose one supported static image, and start with conservative settings. Straightening modestly tilted receipts, forms, notes, and text-heavy scans before reading, archiving, or placing them in a PDF.
- Run the bounded local operation: Process the decoded pixels in this browser; stop and adjust instead of accepting an ambiguous result. Automatic mode evaluates bounded candidate rotations from sampled luminance structure and chooses the strongest alignment score; manual mode uses the entered angle. The image is rotated onto a new flattened canvas.
- Inspect the flattened result: Inspect long baselines and page edges at high zoom, compare automatic and manual angles, check that no corner content was clipped, and reopen the PNG before using it as an archival or PDF source.
Important limitations
Angle estimation is heuristic and works best on pages with clear horizontal text or lines. Sparse artwork, handwriting, photographs, perspective distortion, large rotation, or multiple orientations can produce a wrong estimate; this is not OCR.
Verify the downloaded result
Inspect long baselines and page edges at high zoom, compare automatic and manual angles, check that no corner content was clipped, and reopen the PNG before using it as an archival or PDF source.
Private by design
Your files stay in this browser. The tool does not upload the source or output to our servers.
Questions and answers
When is this tool useful?
Straightening modestly tilted receipts, forms, notes, and text-heavy scans before reading, archiving, or placing them in a PDF.
What does the local operation do?
Automatic mode evaluates bounded candidate rotations from sampled luminance structure and chooses the strongest alignment score; manual mode uses the entered angle. The image is rotated onto a new flattened canvas.
Which limitations matter?
Angle estimation is heuristic and works best on pages with clear horizontal text or lines. Sparse artwork, handwriting, photographs, perspective distortion, large rotation, or multiple orientations can produce a wrong estimate; this is not OCR.
How should I verify the result?
Inspect long baselines and page edges at high zoom, compare automatic and manual angles, check that no corner content was clipped, and reopen the PNG before using it as an archival or PDF source.