All Files Viewer

Review by eFreeware

All Files Viewer is a free document reader for Android from Nullbyte Labs, listed in the Productivity category and rated for Everyone. It has been installed more than 10 million times and holds a 4.2 average from 9,966 ratings, which puts it among the more widely used PDF viewers on the platform. The pitch is straightforward: open PDFs and text files, tidy up the ones you no longer need, and keep the sensitive ones behind a password.

What makes it worth a look is the combination of reading and light housekeeping in one place. Rather than treating a PDF as something you only glance at, the app lets you delete documents you are finished with and shows you where each file actually lives on your device, so you are not hunting through folders afterward. For anyone whose phone has become the place where contracts, tickets and manuals pile up, that is a more useful set of features than a flashy viewer alone.

It is also a young app, first released on June 10, 2025, and the most recent update landed on August 31, 2026.

Who this reader is built for

The clearest fit is someone who deals with PDFs on a phone as a matter of routine: a student working through lecture handouts, a freelancer checking invoices before sending them on, or anyone who receives documents by email and wants to read them without opening a desktop. The password lock speaks to a slightly different need, the person who keeps bank statements, medical letters or signed agreements on a handset and would rather they were not readable by whoever picks the phone up next.

The txt support widens that audience a little. Plain text files are easy to overlook, but they turn up in the form of readme files, exported notes and configuration snippets, and having them open in the same app as your PDFs saves installing something else for the occasional glance.

I would not frame this as a tool for heavy document editing or for building a personal library with covers, tags and reading progress. The developer describes a viewer and manager, and that is the shape of the offer: read it, find it, share it, delete it, lock it if it matters.

Reading, sharing and clearing out documents

The core of the app is document viewing. PDFs open quickly, according to the developer, and the reading interface is described as simple and attractive, which matters more than it sounds: a viewer you use daily should get out of the way rather than decorate the page. Txt files open in the same environment, so a quick look at a plain text note does not require a second app.

Sharing is handled inside the app as well, so a PDF you have just read can be passed to a friend or colleague without leaving the viewer to find it again in a file manager. It is a small convenience, but it is the sort of thing that decides whether an app stays installed.

Managing files is the other half. You can delete documents you no longer need directly from the app, which keeps the phone from filling up with duplicates and outdated downloads. The app also displays the file path of whatever you are viewing, which makes it easier to work out where a document came from and where it is stored if you need to move it later.

Password protection for sensitive PDFs

The feature that stands out most is the ability to lock important PDFs with a digital password and unlock them again when required. For documents you would not want a family member, a colleague or a stranger to browse through, that adds a layer the average viewer does not bother with.

How much that matters depends on your habits. If the PDFs on your phone are takeout menus and boarding passes, the lock will sit unused. If they include anything with an account number or a signature on it, having the option inside the same app you read everything else in is a reasonable argument for choosing this one over a bare-bones reader.

It is worth treating the lock as a convenience rather than a vault. The developer presents it as a way to keep PDF documents secure, and it does exactly what it says on the surface: a password stands between the file and anyone opening it in this app.

What it costs to use

All Files Viewer is free to download and it carries ads. There are no in-app purchases, so there is no paid tier to weigh against the cost of a paid alternative.

You get the reading, sharing, deleting, path display, txt support and password locking at no charge, and you accept advertising in return.

How it compares with other document tools

The obvious alternative is a full office suite that happens to open PDFs among spreadsheets and slide decks. Those apps do more, but they are heavier and usually want you inside an account ecosystem. All Files Viewer stays close to a single job, which is an advantage if documents are all you need to handle.

A dedicated PDF editor is the other direction. Editors let you change text, merge files and fill in forms, and they tend to charge for it. This app is a reader and organizer, so the comparison comes down to whether you need to alter a document or only to read, store, share and remove it.

There are also the minimal viewers that do nothing but render a page. Choosing between those and All Files Viewer mostly comes down to whether the extras here, the password lock, the file path display and the delete option, are things you would actually use.

A dependable pick for everyday PDF reading

All Files Viewer does a small set of things and does them without asking for money. Reading PDFs and txt files, sharing them, deleting what you are done with, seeing where a file lives and locking the ones that matter is a coherent package for a free app, and the install and rating figures suggest plenty of people have found it adequate for the job.

It suits anyone who wants a lightweight way to deal with documents on Android, and it suits people who keep a few sensitive PDFs on their phone and would like them behind a password. If your needs run to editing pages or managing a large, tagged library, a full document suite will serve you better.

Given that it is free and ad-supported, the cost of trying it is your time and a bit of screen space. For routine reading and tidying of PDFs, that seems a fair exchange.