PERSPECTIVE
☞ runs entirely in your browser — nothing is uploadedDrop your image here
or click to browse — JPG, PNG, WebP
Drag corners on source
Corrected preview
OneImageTool
Free Image Tools
PERSPECTIVE
Drag four corner handles to flatten skewed scans, whiteboards and building photos — warped output updates live.
or click to browse — JPG, PNG, WebP
Drag corners on source
Corrected preview
flatten skew
Photograph a document from anywhere but directly above and it comes out as a trapezoid — the near edge longer than the far one. Put the four handles on the four corners of the subject and the tool stretches that quadrilateral back into a rectangle, so the page reads flat and the text lines run parallel again.
The output size is taken from your own corners: the width of the longer horizontal edge and the height of the longer vertical one. Nothing is upscaled beyond that, so a document photographed at a steep angle comes back at the resolution of its widest side, not of the original frame.
three steps
A skewed JPG, PNG or WebP. Full resolution helps — the correction stretches part of the image, and the stretched part is where softness shows.
Drag each handle onto the actual corner of the subject, not onto the edge of the photo. Zoom in on the two far corners in particular; a few pixels of error there becomes a visibly crooked edge after the stretch.
Export as PNG when the result is a document you plan to read or run through OCR, since JPG artifacts sit right on the letterforms.
quick answers
Your four corners define a quadrilateral. Every output pixel is mapped back into that quad by interpolating between the corners, and the colour is sampled bilinearly from the four nearest source pixels. It is a manual keystone fix, done in one pass over the image.
Not exactly. A projective transform compresses the far end of the subject the way a lens does; this interpolates evenly between the corners instead. On a mild angle the difference is invisible. On a steep one, content near the far edge comes out slightly too large.
Because the far part of the subject occupied fewer pixels in the photo and has been stretched to fill the same width as the near part. There is no extra detail to stretch into, so it interpolates. Shoot squarer to the subject if sharpness matters.
Yes. Reset corners puts them back at the full image bounds, and you can start placing them again.
A four-corner fix cannot follow a curve. It will straighten the outline and leave the text near the spine bowed. Flatten the page physically, or photograph one page at a time closer to square.
Usually a lot. Most text recognition assumes horizontal baselines, and a keystoned page breaks that assumption before the recogniser sees a single character.
No. The warp runs on a canvas in your browser.
Yes — free with no watermark.