Deskew

Nobody scans perfectly. Feed a page into a scanner slightly off-square, or photograph a document at a casual angle, and you get text that runs downhill across the page. PDFora's deskew tool straightens crooked scans inside your browser: it measures how far each page leans and rotates it back to level, so the result looks like it came off a proper flatbed scan.

There are two ways to work. Auto-detect analyzes the page, finds the tilt angle on its own, and corrects it, which handles most scans in one click. Manual mode gives you a degree control instead, useful when a page has little text for the detector to lock onto, or when you want to nudge the correction by a fraction of a degree yourself.

The correction runs locally, so your scanned contracts and records are never uploaded anywhere. Deskewing is free, needs no signup, leaves no watermark, and has no usage cap. It also pays off downstream: straightened pages OCR more accurately, print more cleanly, and simply look like you cared.

How to deskew a PDF online

1. Open the Deskew tool on PDFora in your browser.
2. Add your crooked scan by dragging the PDF in or selecting it from your device.
3. Choose Auto-detect to let the tool find each page's tilt angle, or switch to Manual mode.
4. In Manual mode, set the rotation in degrees until the preview shows level text.
5. Apply the correction and let your browser straighten every page locally.
6. Compare the preview against the original, then download the straightened PDF.

When to use this tool

• Straightening a lease agreement that was photographed on a phone at an angle before sending it to a landlord.
• Fixing a batch of receipts that went through a sheet-fed scanner slightly rotated, so they file neatly in an expense system.
• Leveling old family letters and certificates digitized from a shoebox, where every page came out at a different tilt.
• Preparing crooked scans for OCR, since recognition accuracy drops sharply when text lines are not horizontal.
• Cleaning up a scanned book chapter where the pages curved near the spine and picked up a lean.
• Squaring up signed forms before submitting them to an official portal that will be viewed and printed by clerks.

Tips for the best results

• Run deskew before OCR, always. Even a two-degree tilt measurably hurts text recognition, and straight input is the cheapest accuracy boost available.
• Trust auto-detect on text-heavy pages. It reads the text lines to find the angle, so ordinary letters, forms, and reports correct themselves reliably.
• Switch to manual for sparse pages. Drawings, photos, or pages with only a few words give the detector little to work with, and setting the degrees yourself is quicker.
• Small angles matter. A correction of even one degree is visible in print, so do not skip deskewing just because the tilt looks minor on screen.
• Deskew fixes rotation, not perspective. A photo taken from an angle has keystone distortion that rotation cannot cure; rescan flat if the page looks trapezoidal.