Use this guide with a free ScanScore resource

You hold the phone over the sheet and nothing happens, or the result looks wrong. Almost every phone OMR problem comes from one of five things: light, flatness, framing, print quality or the way the sheet was filled. Work through this list in order and you will fix nearly all of them.

The app will not capture

  • Show the whole frame. All four corner marks and the black frame must be inside the picture.
  • Hold still. Auto capture waits until the paper is square and steady.
  • Move back a little. Too close and a corner falls out of view.
  • Check you are scanning the right exam. A sheet from a different layout will not match.
  • Use the manual shutter for an awkward sheet.

Light and shadows

  • Avoid your own shadow falling across the sheet.
  • Avoid glare from a window or lamp on glossy paper.
  • Even, soft light beats bright, hard light.

The sheet is not flat

  • Lay it on a table, not in your hand.
  • Flatten curled sheets under a book for a minute.
  • Folded sheets: press the fold flat; a crease through a corner mark is the worst place.

Marks read wrongly

  • Faint marks. Pale pencil or a light pen can look empty. Ask students to fill darkly.
  • Partial erasures. A smudge can look like a second answer. Review the paper and fix it.
  • Double marks. The app flags them for you; choose the right answer by hand.
  • Mismatch with the key. Check the key was entered for the right set and number of questions.

You can look through any scanned paper and change a mark before saving. See reviewing and correcting a scan.

Roll number problems

  • Make sure each digit has exactly one bubble filled.
  • Check the roll length on the exam matches what students were told.
  • For duplicates, remember a second scan of the same roll replaces the first.

More in roll numbers on an OMR sheet.

It is the print, not the scan

  • Corner marks cut off by the printer? Print at actual size and recheck.
  • Faint print? Replace the cartridge or use normal quality instead of draft.
  • Photocopy? Print a fresh sheet from the PDF.

Printing details are in OMR sheet printing tips.

The phone itself

  • Wipe the camera lens.
  • Close other heavy apps; free some memory.
  • Let a hot phone cool down.
  • Update the app to the latest version.
Still stuck? Scan the same sheet on a different table and in different light. If it works there, the problem was the setting, not the sheet or the app.

The background on why sheets are reliable is in phone OMR scanning accuracy.

Keep reading: How to fill an OMR sheet (student guide) · OMR on a budget Android phone