Deskew an Image Online

How this works

Deskewing straightens a tilted or skewed scan or photo so that rows of text and the page edges sit truly level instead of leaning a few degrees off.

Rather than a flat rotate, it squares the page through its four corners — set automatically on open or by hand — and maps them to a level rectangle with the same perspective warp, which fixes both a simple tilt and the more complex slant from an angled photo in one step.

What you get

Level lines look tidier and, crucially, read far more accurately in OCR (text-recognition) tools, which struggle with slanted text.

Save the straightened page as a PNG or PDF; pair it with the Black & White filter for the cleanest, highest-contrast input before running OCR.

Tip

Deskew first, then apply Black & White, then run text recognition — level lines plus a pure black-on-white page give OCR engines the cleanest possible input.

Enhance filters explained

After the page is straightened, an enhance filter cleans it up. Each one is applied to the corrected scan in your browser; here is exactly what they do and when to use each.

Magic (colour)

Stretches contrast about 1.35× around mid-grey and adds a small brightness lift, so dull greys become white and text deepens — the classic colour-scan look. Colour is kept. Best for: Most documents, and anything with colour you want to keep (logos, highlights, coloured forms).

Black & White

Measures the page's average brightness, biases the cut-off toward white paper (≈0.82× the mean), then forces every pixel to pure black or pure white. The result is a clean, high-contrast bi-tonal page. Best for: Text-only pages, and the cleanest input for OCR; also gives the smallest PDF.

Grayscale

Converts to neutral grey using the standard Rec. 601 luma weights (0.299 red + 0.587 green + 0.114 blue), keeping soft tones without colour. Best for: Pages with photos or shading where pure black-and-white would lose detail, but colour isn't needed.

Original

Leaves the warped pixels exactly as photographed — perspective is still corrected, but no contrast, brightness or colour change is applied. Best for: When you only want the page straightened and cropped, or you'll do your own colour edits afterwards.

PDF page sizes

Save a PNG, or a single-page PDF in one of these sizes. Fit makes the page exactly the scan's pixels (no margins); A4 and Letter centre the scan on a standard page. Sizes are shown in millimetres, inches and PDF points (1 pt = 1/72 in).