How to scan documents on Android into a clean PDF

1. Get the light right

Even daylight from a window is best. Avoid a single lamp to one side, which throws a shadow across half the page, and keep your own shadow off the paper by standing so the light comes from in front of you. In a dim room, the phone's flashlight helps, but hold the phone a little higher so the flash does not leave a bright spot.

2. Use a dark, plain background

White paper on a dark table gives the scanner a clear edge to find. A white page on a white desk, or on a patterned tablecloth, is much harder to outline correctly.

3. Hold the phone flat above the page

Keep the phone parallel to the paper, with the whole page in view and a little margin around it. A scanner app can straighten a page photographed at an angle, but the less it has to correct, the sharper the text stays.

4. Check the corners

A good scanner detects the page edges on its own. Before you save, glance at the outline: if a corner is cut off or a bit of table is included, drag the corner to the right place. It takes a second and saves a rescan.

5. Pick the right filter

• Original keeps the page exactly as photographed. Use it for photos, colour documents and anything with stamps or signatures you want to look real.
• Auto flattens shadows and uneven light into even white paper, like a flatbed scan. The best choice for most documents.
• Gray or B&W make text crisp and files small. Good for printed text and handwritten notes.

6. Keep multi-page documents in one file

A contract or a form with several pages belongs in one PDF, in the right order, not in five separate files. Scan the pages one after another into the same document, then check the order before you save.

7. Name it so you can find it again

“Scan 14” means nothing in six months. Name the document by what it is, such as “Lease agreement 2026”, and if your app supports it, mark what kind of paper it is.

Doing this in Keepscan

Keepscan outlines the page live and takes the shot by itself once you hold steady, or you can switch to manual. There is a flashlight for dim rooms, corners you can fine-tune by hand, and Original, Auto, Gray and B&W filters. Add pages any time, drag them into order, then save a PDF or JPG images to your phone or share them to any app. Scanning, saving and sharing are free, with no watermark and no account.