Frequently asked questions

PDF Viewer is free to use. It contains no ads and never adds a watermark to your documents (unless you choose to add your own with the Watermark tool).

Android 9 (API 28) and newer, on phones and tablets.

No. Reading, annotating, merging, splitting, compressing, protecting and converting all work offline. The document scanner is provided by Google Play services and may download its scanner component once the first time you use it.

English and Hindi. It follows your phone language. On Android 13 and newer you can also pick the app language in Android Settings → System → Languages → App languages.

No. Everything happens on your phone. PDF Viewer has no accounts, no ads and no analytics, and your files are never sent to our servers. See the privacy policy.

No. When you annotate, merge, compress or otherwise change a file, the result is saved as a new PDF in the Output tab. The original stays as it was.

PDFs go to Documents/PDF Viewer and exported images to Pictures/PDF Viewer, so you can also find them with any file manager. On Android 9 they are stored in the app’s own folder (Android/data/com.kaafisir.pdfviewer/files).

PDFs are created by many apps (browsers, WhatsApp, e-mail…). Android only lets an app list all of them with this permission. It is used only to find PDF files — nothing is uploaded. You can decline and add folders manually with Choose folder, or open files from your file manager.

Yes. Turn on App lock in Settings → Privacy. The app then asks for your fingerprint, face or screen lock when it opens or after 30 seconds in the background.

Yes. Tap the theme button in the reader to cycle through Day, Night and Sepia, and adjust brightness in Reading.

Yes, enter the password when asked. If you have forgotten it, nothing can open the file — passwords cannot be recovered.

Some PDFs are scans, which are only pictures of pages. PDF Viewer does not perform OCR (text recognition) yet, so there is no text to search or select in those files.

Yes. Open the ⋮ menu in the reader and choose Read aloud. It uses your phone’s text-to-speech engine, so the voices and languages depend on your device settings.

You can add text anywhere on a page with the Text tool, add your signature, and draw ticks or marks. Interactive PDF form fields (tap-to-type form boxes) are not supported yet.

No. PDF Viewer is for marking up, signing and organizing PDFs. You can highlight, draw, add notes and images, rearrange pages and more, but the original text is not editable.

Light, Balanced and Strong recompress the pictures inside the PDF and keep your text selectable. Maximum turns each page into an image for the smallest file, which makes text non-selectable. If a file cannot get smaller you will be told.

Yes. PDF Viewer uses standard PDF encryption (AES, 256-bit where supported). Choose a strong password and keep it safe — it cannot be recovered.

Unlock them first with Tools → Unlock, then run the tool on the unlocked copy.

JPG, PNG, WebP and HEIF photos. Rotation from your camera is respected automatically.

Please use the report form or e-mail support@fireclashpro.com. Tell us your phone model and Android version.

Uninstall it like any app. Files you created stay in Documents/PDF Viewer and Pictures/PDF Viewer until you delete them. To clear the recent list and cache first, use Settings inside the app.