Rotate PDF Pages to Fix a Sideways Scanned Certificate

A scanned certificate often opens sideways. The scanner or phone app saved the sheet in landscape, so the viewer shows the text running from top to bottom. Application portals for SSC, UPSC and most state commissions preview what you upload, and a marksheet lying on its side is the kind of thing that gets flagged during document verification.

This tool rotates every page of a PDF by 90 degrees to the left or to the right. Pick the file, press one button, download the result. It changes the rotation setting stored inside the PDF rather than redrawing the page, so the scan keeps its original sharpness and the file size stays almost the same.

The file never leaves your device. The rotation is done by your browser with the pdf-lib library and nothing is uploaded to a server, which matters when the document carries your Aadhaar number, roll number or signature.

1. Click the upload box or drop your PDF on it. The tool takes one file at a time.
2. Read the page count shown under the box. The rotation will apply to all of those pages.
3. Press Rotate left for 90 degrees anticlockwise, or Rotate right for 90 degrees clockwise.
4. Wait for the green Ready panel, which shows the new file name and its size.
5. Press Download. The file is saved under the original name with -rotated added at the end.
6. Open the download and check it. If it needs a further quarter turn, press the same button again; the line under the box shows the total rotation, so two presses give 180 degrees.

The two buttons are the only controls. Each press adds 90 degrees in that direction to a running total, shown under the page count as Current, and applies that total to the file you picked, so pressing Rotate right twice turns every page by 180 degrees and a third press by 270. The page is not re-rendered or recompressed.

Because the total is always applied to the original file, you can press left after right to undo a turn, and the download you get carries the total shown, whatever the order of your presses.

If a page already carries a rotation value from the scanner, the tool adds to it. A page stored at 270 degrees that you rotate right ends up at 0, which is why a scan that looked wrong can come out upright after one press even though its internal value went round the clock.

A PDF page can carry a rotation attribute that tells the viewer how to display it. This tool sets that attribute. The image of your certificate inside the file is untouched, so there is no loss of quality and no change to the resolution. The output is usually within a few kilobytes of the original.

Browser viewers, Adobe Reader and the previews on government portals all honour this attribute. A small number of older converters that turn PDFs into images ignore it. If a page still shows sideways after rotating, convert the page to an image with the PDF to JPG tool, rotate the image, and rebuild the PDF from it.

• Rotation applies to the whole document. There is no way to pick individual pages here. For a file where only page 3 is sideways, extract that page, rotate it, and merge it back using the Extract pages and Merge PDF tools.
• Password-protected or encrypted PDFs cannot be opened. The tool shows an error asking for a valid, unencrypted PDF. Remove the password in the application that set it, then try again.
• Only 90 degree steps are available. A scan that is slightly tilted (a few degrees off) needs to be rescanned or straightened in an image editor.
• Very large files depend on the memory of your phone or laptop, since the whole PDF is loaded in the browser. A scanned marksheet of a few megabytes is no problem.

Rotation runs entirely in your browser. The PDF is never uploaded, and closing the tab removes it from memory.