How to Scan Documents to PDF on Android

Turning a physical document into a PDF using only your Android phone has become genuinely good — modern phone cameras combined with built-in scanning software produce results that are clear, properly proportioned, and appropriately compressed. You don't need a flatbed scanner for most document scanning tasks anymore.

Method 1: Google Drive's built-in scanner (fastest)

Every Android phone with Google Drive installed — which is essentially every Android phone outside of China — has a document scanner built in. It's one of the best available because Google's processing automatically corrects perspective, enhances contrast, and outputs a properly sized PDF.

Open Google Drive on your Android phone
Tap the blue + button in the bottom right corner
Tap "Scan" — a camera view opens with document detection enabled
Position the document in the frame. Drive automatically detects document edges and waits for the image to be stable before capturing
Review the scan — you can retake it or crop/adjust the detected edges
Add more pages if needed (for multi-page documents)
Tap Save — the document is saved as a PDF directly to your Google Drive

The output is a compressed PDF with the text layer preserved — meaning the PDF is searchable (you can Ctrl+F for text in it) rather than just an image.

Method 2: Samsung Notes or Samsung's built-in scan

Samsung phones have scan capabilities built into multiple places. The most accessible is through Samsung Notes:

Open Samsung Notes (pre-installed on all Samsung phones)
Create a new note and tap the attachment icon
Choose "Add attachments" then "Scan"
Scan your pages and the result is embedded in the note
Export the note as a PDF

Alternatively, Samsung phones from the Galaxy S series onwards have a "Scan documents" shortcut in the camera app — accessible by swiping left in the camera viewfinder to reach the "More" modes section.

Method 3: Microsoft Lens (best for paper documents)

Microsoft Lens is a free app available on Android that's specifically designed for document scanning. It's particularly good at handling white paper in variable lighting conditions:

Install Microsoft Lens from the Play Store (free)
Select "Document" mode
Hold your phone over the document — Lens automatically detects and captures when the document is in frame
Adjust edges if needed
Export directly to PDF, OneDrive, Word, or your phone's gallery

Microsoft Lens also has a "Whiteboard" mode that's excellent for photographing handwritten notes, meeting notes on whiteboards, and hand-drawn diagrams.

Getting the file size right after scanning

A common problem with phone-scanned documents is file size. Google Drive typically produces well-compressed output, but other scanning methods can produce large files — a 10-page document might scan to 8-15MB. If you need to send it by email or upload it to a portal with a size limit, compression is necessary.

After saving your scanned PDF to your phone, open Chrome on Android and go to pdf99.org/compress-pdf. Upload the scanned PDF and use the quality slider to compress it. A quality setting of 60-75% typically reduces scanned documents by 60-80% while keeping text completely legible. The compressed file saves back to your phone and is ready to share.

Tips for getting clear scans

Lighting is the most important factor. Natural light from a window — positioned so it illuminates the document without creating glare — produces the best scans. Avoid scanning in dim artificial light, which forces the camera to increase ISO and introduces noise that makes text look grainy in the output.

Flatten the document before scanning. A slightly curled page creates curved text that looks poor in the output even after perspective correction. For important documents, place them on a flat surface and use something light to hold down the edges if they're curling.

Hold the phone parallel to the document surface — directly above it, not at an angle. Automatic perspective correction handles modest angles well, but extreme angles produce distorted output that no amount of correction can fully fix.

Compress your scanned PDF — free

Works in Chrome on Android. No app required.

Compress PDF →

Choosing the right scanning app for your needs

The three methods covered above — Google Drive, Samsung Notes, and Microsoft Lens — are the most reliable free options, but they have different strengths. Google Drive is the best all-rounder: available on every Android device, produces searchable PDFs with good automatic processing, and integrates directly with cloud storage. Use it as your default.

Samsung's built-in scanner is faster to access if you're on a Samsung device since it's in the camera app, but the output goes to Gallery or Notes rather than directly to a PDF file you can share. There's an extra step of exporting from Notes to PDF.

Microsoft Lens produces the cleanest output for white-paper documents in challenging lighting conditions. Its processing algorithm handles shadows, uneven lighting, and slight curves in the paper better than most other apps. If you frequently scan documents in offices or classrooms with fluorescent lighting and mixed shadows, Lens is worth having as a backup.

Making scanned PDFs searchable

A major limitation of phone-scanned documents is that they're image-based — the text you can read visually is actually just pixels in a photograph. You can't Ctrl+F to search within the document, and accessibility tools can't read the text aloud.

Google Drive's scanner automatically applies OCR (optical character recognition) to create a hidden text layer in the PDF. This makes the document searchable. To check whether your scanned PDF is searchable, open it and try to select text — if dragging highlights words, it has a text layer. If dragging does nothing, it's image-only.

For PDFs scanned with other apps that don't apply OCR automatically, you can add searchability after the fact by uploading to Google Drive and opening with Google Docs. Google will OCR the document and create a version with recognised text. It's an extra step but produces genuinely useful searchable output for important documents.

Scanning multi-page documents cleanly

Multi-page scanning is where phone scanners can get messy if you're not methodical. The key is to scan all pages in a single session rather than scanning individual pages and trying to merge them later. Both Google Drive and Microsoft Lens allow you to add additional pages before saving — after scanning the first page, look for an Add Page button and continue scanning without stopping.

Scan pages in order. It sounds obvious but it's easy to scan out of order when handling a physical document. Lay the document flat, scan page 1, then immediately scan page 2, and so on. Don't scan all the odd pages then all the even pages — the app records pages in scanning order.

For long documents over 20 pages, consider scanning in sections of 10-15 pages and then merging the resulting PDFs using PDF99's merge tool. Scanning 50 pages in one session with a phone is prone to mistakes — a missed page or a bad scan means you might not notice until you're done and have closed the session.

Reducing file size after scanning

As mentioned earlier, phone-scanned PDFs are often larger than they need to be. A 10-page document scanned with Google Drive typically produces a PDF of 3-8MB. For sharing by email or uploading to a portal, this is often too large.

After saving your scanned PDF to Google Drive or your device, open Chrome on Android and go to pdf99.org/compress-pdf. Upload the PDF, use the quality slider at 65-75%, and download the compressed version. For most scanned documents this produces a file 50-70% smaller with no significant visible quality loss. If you have a specific size target, the dedicated compression tools (200KB, 500KB) handle the compression automatically.