How to Sign a PDF on Android — 3 Easy Methods

Signing PDFs on Android

Android does not have a single built-in PDF signing tool the way iPhones have Markup. But that does not mean signing a PDF on Android is difficult. There are three reliable methods, and the best one does not require installing any app at all.

This guide walks through each method step by step: SigPDF in Chrome (our recommended approach), Google Drive, and Adobe Fill & Sign. By the end, you will know exactly which option to use and when.

Method 1: SigPDF in Chrome (Recommended)

The simplest and most capable way to sign a PDF on Android is to use SigPDF directly in Chrome or any other browser. No app to download, no account to create, no permissions to grant. Your PDF is processed entirely on your phone and never uploaded to any server.

Step-by-Step Instructions

1. Open Chrome (or any browser) on your Android phone and go to sigpdf.com
2. Tap the upload area and select your PDF. You can browse your Downloads folder, internal storage, Google Drive, or any other file source your phone supports
3. The PDF loads in the viewer. Swipe through pages to find where your signature is needed
4. Tap "Add Signature" and choose your preferred method:
   • Draw — use your finger to sign directly on the touchscreen. Android phones handle touch input well, and the result looks natural
   • Type — enter your name and select from handwriting-style fonts. This is the fastest option and produces the cleanest result on a phone screen
   • Upload — select a saved image of your signature from your gallery
5. Position your signature on the document. Tap to place it, then drag to adjust the position. Pinch to resize until it fits the signature line properly
6. Add text and dates if the document requires them. Tap "Add Text" to insert your printed name, job title, date, or any other information the form needs
7. Tap "Confirm & Download" to save the signed PDF. The file saves to your Downloads folder. From there, you can email it, share it through any messaging app, or upload it to cloud storage

Why This Method Is Best for Android

No app installation. Android's app ecosystem for PDF signing is cluttered with low-quality apps, ad-heavy tools, and questionable privacy practices. Using SigPDF in Chrome avoids all of that — no app store search, no storage used, no background processes.

Full feature set. You get drawn signatures, typed signatures, image uploads, text fields, and date stamps. Most Android PDF apps only offer drawn signatures in their free tiers.

Privacy. Your PDF is processed entirely inside Chrome on your phone. The document is never uploaded to any server. This is important for contracts, tax forms, medical documents, or anything containing personal information.

Universal compatibility. This same method works identically on any Android phone — Samsung, Google Pixel, OnePlus, Xiaomi, or any other brand. You do not have to worry about manufacturer-specific features or Android version differences.

Method 2: Google Drive

If you already use Google Drive, you can annotate PDFs directly within the app. This is not a dedicated signing tool, but it works for basic signatures.

Step-by-Step Instructions

1. Upload your PDF to Google Drive if it is not already there. Open the Google Drive app, tap the "+" button, and select "Upload." Choose your PDF from your phone's storage
2. Open the PDF in Google Drive by tapping on it
3. Tap the annotation icon — look for a pen or edit button in the toolbar (the exact appearance varies by Android version and Drive app version)
4. Select the pen tool from the annotation toolbar
5. Draw your signature directly on the document using your finger. You may want to zoom in to the signature area first for better precision
6. Save the annotated PDF. The changes save to your Google Drive. You can then download the file or share it directly from Drive

Pros of Google Drive

• Already installed on most Android phones
• No additional app download needed
• Syncs the signed document to your Google account automatically
• Works with files already stored in Drive

Cons of Google Drive

• Not designed for signing. The annotation tool is a freehand drawing tool, not a signature tool. There are no signature-specific features like typed signatures, snap-to-line placement, or signature resizing
• Inconsistent experience. The annotation features vary depending on your Android version, Google Drive app version, and device manufacturer. Some users may not see annotation options at all
• No typed signatures. You can only draw with your finger
• Requires a Google account and internet connection to access Drive
• Cloud-based. Your PDF is uploaded to Google's servers. For sensitive documents, this may be a concern
• Drawing quality is basic. The pen tool is not optimized for signatures, so the result can look rough

Method 3: Adobe Fill & Sign App

Adobe offers a dedicated mobile app for filling out and signing PDF forms. It provides more signing-specific features than Google Drive, though it comes with trade-offs.

Step-by-Step Instructions

1. Download Adobe Fill & Sign from the Google Play Store. The app is free but requires an Adobe account for some features
2. Open the app and tap "Select a file to fill out"
3. Choose your PDF from your phone's storage, email, or camera (you can photograph a paper document)
4. Tap the signature icon in the toolbar — it looks like a pen nib
5. Create your signature. You can draw it with your finger or type your name. Adobe saves it for future use
6. Tap on the document where you want the signature placed. Drag to reposition and use the handles to resize
7. Tap "Done" and share or save the signed PDF

Pros of Adobe Fill & Sign

• Purpose-built for form filling and signing
• Saves your signature for reuse across documents
• Supports both drawn and typed signatures
• Recognizes form fields automatically in many PDFs
• Well-known brand with a long track record

Cons of Adobe Fill & Sign

• Requires app download — takes up storage space on your phone
• Adobe account required for full functionality
• Documents may be processed on Adobe's servers, which raises privacy concerns for sensitive files
• Upsell pressure. Adobe frequently promotes upgrades to Acrobat Pro within the app
• App size. Adobe apps tend to be large and resource-intensive, which can affect performance on budget Android phones
• Occasional bugs. User reviews on the Play Store report issues with crashes and file compatibility on certain Android devices

Comparison: Which Android Method Should You Use?

| Feature | SigPDF (Chrome) | Google Drive | Adobe Fill & Sign | |---|---|---|---| | App download required | No | No (pre-installed) | Yes | | Account required | No | Yes (Google) | Yes (Adobe) | | Drawn signatures | Yes | Yes (basic) | Yes | | Typed signatures | Yes | No | Yes | | Image upload | Yes | No | No | | Add text and dates | Yes | No | Yes | | Privacy (local processing) | Yes | No (cloud) | Partial | | Works on all Android devices | Yes | Varies | Yes | | Signature saved for reuse | No | No | Yes | | Free | Yes | Yes | Free with limits |

Use SigPDF when:

• You want the most complete signing experience without installing anything
• Privacy matters and you do not want your PDF uploaded to a server
• You need typed signatures, text fields, or date stamps
• You want a method that works identically on any Android phone

Use Google Drive when:

• The PDF is already in your Google Drive
• You only need a quick, basic drawn signature
• You do not want to open a browser or install an app

Use Adobe Fill & Sign when:

• You sign PDFs frequently and want your signature saved for reuse
• You need to fill out complex form fields that Adobe can auto-detect
• You are comfortable with installing an app and creating an Adobe account

Tips for Better Signatures on Android

Rotate to Landscape

Turn your phone sideways when drawing your signature. The extra width makes a significant difference in how natural your signature looks. Most signatures are wide and short, and portrait mode constrains the horizontal space.

Use Your Fingertip, Not Your Nail

Android touchscreens are capacitive and respond to the pad of your finger. Sign with the soft part of your fingertip using moderate pressure. Slow, deliberate strokes produce smoother lines than fast, sketchy ones.

Try a Typed Signature

If your finger-drawn signature looks messy on a phone screen, there is no reason to force it. A typed signature in a script font is legally valid and often looks more professional. SigPDF offers several font choices that produce clean results.

Zoom In Before Placing

Pinch to zoom into the signature area before positioning your signature. This prevents the common problem of a signature that is slightly off the line or overlapping other text.

Is an Android PDF Signature Legally Valid?

Yes. An electronic signature created on any device, including an Android phone, is legally binding under the ESIGN Act (US), eIDAS (EU), and similar legislation worldwide. The type of device does not affect the legal validity. For more details, see our guide on electronic signature legal validity.

Sign Your PDF on Android Now

Open SigPDF in Chrome on your Android phone and sign your document in under a minute. No app to install, no account to create, and your files never leave your device.

Sign PDF on Android -->

Frequently Asked Questions

Can I sign a PDF on Android without downloading an app?

Yes. Open sigpdf.com in Chrome or any browser on your Android phone. Upload your PDF, add your signature (drawn, typed, or uploaded image), and download the signed file. No app installation is needed.

What is the best free PDF signing app for Android?

For most people, a browser-based tool like SigPDF is better than a dedicated app. It requires no download, no account, and provides full signing features with complete privacy. If you prefer a native app, Adobe Fill & Sign is a solid option, though it requires an Adobe account and may process files on Adobe's servers.

How do I sign a PDF from an email on my Android phone?

Save the email attachment to your phone's Downloads folder. Then open sigpdf.com in Chrome, upload the saved PDF, sign it, and download the result. Attach the signed PDF to your reply email. This works with Gmail, Outlook, and any other email app on Android.

Can I sign PDFs on a Samsung phone specifically?

Yes. Samsung phones with One UI may also have built-in PDF annotation through Samsung Notes or the Samsung PDF viewer. However, these tools are basic and vary by model. SigPDF works identically on all Samsung phones through the browser and provides a more complete signing experience.