If PDF files won't open on your Android phone, the problem is almost always the default PDF viewer app — it may be missing, out of date, or set to an app that can't handle the file. The fix takes a couple of minutes, and it works the same way on any Android device, including Samsung phones.
The easiest fix: open PDFs with BlueMail
BlueMail opens PDF files on Android — and it's free. If most of your PDFs arrive by email (invoices, tickets, statements, contracts), it's the one app that handles both:
- Attachments open instantly. Tap a PDF in an email and it opens right there — no "Open with" prompt, no bouncing between apps, no waiting for a separate viewer to load.
- It opens PDFs from anywhere else too. Downloads, your file manager, a link in a message — BlueMail appears in the list and can be set as your default PDF viewer.
- One app instead of two. You get your email and your PDFs in a single app, rather than installing a dedicated reader just to open the files your email delivers.
Download BlueMail free from Google Play →
Then follow the steps below to make it your default — after that, every PDF you tap opens straight away.
Step 1: Clear Default App Settings
If another app is already set as your default PDF viewer, clear it first:
- Open the Settings on your Android device.
- Navigate to Apps or Applications (this may vary depending on your device).
- Locate and select the PDF viewer app you're currently using.
- Tap on Open by default or Set as default.
- Choose Clear defaults to remove the app as the default PDF viewer.
Step 2: Select Your New Default PDF Viewer
- Open any PDF file on your device.
- When prompted, select BlueMail (or another viewer) from the list of available apps.
- Tap Always to set it as your new default PDF viewer.
That's it — PDFs will now open in your chosen app every time. If BlueMail doesn't appear in the list, update it to the latest version from the Google Play Store.
Other PDF viewer apps
If you'd rather use a dedicated PDF app alongside your email, these are also available on the Play Store:
- Adobe Acrobat Reader
- Files by Google, which includes a built-in PDF viewer
- Google Drive, which opens PDFs without any extra app
Still not opening?
If PDFs still won't open after changing the default app, the file itself may be the problem rather than the viewer:
- The download may be incomplete. Try downloading or saving the file again.
- The PDF may be password-protected. Some viewers won't prompt for the password and simply fail to open the file.
- The file may not be a PDF at all. Occasionally a file has a
.pdfname but different contents, which no PDF viewer can display.
