A few months back, I was sitting in a coffee shop, trying to sign a rental agreement my landlord had emailed me as a PDF. I had no printer, no scanner, and honestly, no patience. I just had my phone and about ten minutes before I had to leave for work.
That’s when I realized how many PDF apps on my phone were basically useless. Some couldn’t even open the file properly. One crashed the second I tried to type my name on the signature line. Another wanted me to pay $9.99 a month just to add a checkmark to a form.
So I went down a rabbit hole. Over the next few weeks, I tested a bunch of PDF reader and editor apps on both my Android phone and my partner’s iPhone, just to see which ones actually work in real situations — not just in a demo video.
Here’s what I found, what I liked, what annoyed me, and what I’d actually recommend to a friend.
Why This Even Matters
PDFs are everywhere now. Contracts, tax forms, school assignments, boarding passes, insurance papers, resumes — if it’s official, it’s probably a PDF.
The problem is, most phones don’t come with a proper editor built in. iPhones can technically mark up PDFs using Markup in the Files app, and Android has some basic tools depending on the brand, but neither is great for anything beyond scribbling a signature.
If you’ve ever needed to fill out a form, combine two PDFs, or shrink a file size before emailing it, you already know the built-in stuff falls short pretty fast.
What I Was Actually Testing For
I wasn’t just opening these apps and taking a screenshot. I tried to use them the way a normal person would during a busy week:
- Signing a document quickly without printing anything
- Filling in a form with checkboxes and text fields
- Merging multiple PDFs into one file
- Compressing a large PDF before sending it over email
- Highlighting and adding notes while reading something for work
- Converting a PDF to Word so I could actually edit the text
Some apps handled all of this smoothly. Others made we want to throw my phone across the room.
The Apps That Actually Held Up
1. Adobe Acrobat Reader (Android & iPhone)
I know, I know — Adobe feels like the “obvious” answer, and a lot of people assume it’s bloated or slow. But honestly, the free version is more capable than I expected.
I used it to fill out and sign that rental agreement in under five minutes, sitting right there in the coffee shop. The signature tool remembers your signature after the first time, which saved me later when I had to sign two more documents that same week.
Where it gets annoying is the constant nudging toward Acrobat Pro for things like editing actual text inside a PDF or converting files. That part is genuinely locked behind a paywall.
Good for: Signing, basic form filling, reading long documents comfortably. Not great for: Serious editing without a subscription.
2. Xodo PDF Reader & Editor (Android & iPhone)
This one surprised me. A coworker recommended it after I complained about Adobe’s upsells, and it turned out to be one of the more balanced free options.
I used Xodo to merge three separate PDFs from a work project into one file, and it just worked — no watermark, no popup asking me to upgrade. It also has a solid annotation tool if you’re the type who highlights and leaves comments while reading (I do this constantly with articles I’m researching).
The interface feels a little dated compared to Adobe, but functionally, it gets the job done without nagging you every five seconds.
Good for: Merging files, annotating, reading PDFs comfortably. Not great for: Heavy-duty editing or converting to other formats.
3. Microsoft Office App / PDF Tools (Android & iPhone)
If you already use Word, Excel, or Outlook, this one makes sense as a default. I tested it mainly for converting a PDF into an editable Word document, since I needed to change some text in an old resume I’d saved only as a PDF.
The conversion wasn’t perfect — some of the formatting shifted around — but it was close enough that fixing it took two minutes instead of retyping the whole thing.
It also lets you scan physical documents straight into PDF using your phone’s camera, which came in handy when I needed to send a signed paper form to my accountant.
Good for: PDF to Word conversion, scanning paper documents. Not great for: Fast, lightweight signing on the go.
4. Foxit PDF Editor (Android & iPhone)
This one leans more toward people who deal with PDFs often — like if you’re a student, freelancer, or someone handling contracts regularly.
I liked that Foxit lets you compress large files before sending them, which solved a real problem I had. I once tried emailing a 40MB scanned PDF and it just sat there failing to send. Foxit compressed it down significantly without making the text blurry or unreadable.
The free version has some limits, and a few tools nudge you toward premium, but the compression and merging tools alone made it worth keeping installed.
Good for: Compressing large files, handling multiple documents. Not great for: Casual, occasional use — feels like overkill if you rarely touch PDFs.
5. Apple’s Built-In Files App + Markup (iPhone Only)
I’m including this because a lot of iPhone users don’t realize what’s already sitting on their phone.
If you open a PDF in the Files app or Mail and tap the little markup icon, you can sign, highlight, and add basic text without downloading anything. For quick signatures, this is genuinely fast, and I used it more than once when I didn’t feel like opening a separate app.
The catch is it’s very basic. No merging, no compressing, no real form-filling for complex documents.
Good for: Quick signatures and simple markups. Not great for: Anything beyond the basics.
Step-by-Step: Signing a PDF Without Printing It
Since this was my original problem, here’s exactly how I do it now, using Adobe Acrobat Reader as an example:
- Open the PDF in the app (either from email, downloads, or file storage)
- Tap the fill-and-sign icon, usually shaped like a pen
- Tap where you need to sign — a text box or signature line will pop up
- Choose “create signature,” draw it with your finger, and save it
- Place it on the document and adjust the size if needed
- Save and share directly from the app, either via email or a messaging app
Once you do this two or three times, it becomes second nature. I genuinely can’t remember the last time I printed something to sign it.
Mistakes I Made Along the Way
I want to be honest about a few things that went wrong during my testing, because I think it’ll save you some frustration.
I once compressed a PDF so aggressively that the text became blurry and unreadable when zoomed in. Lesson learned — always check the compressed version before sending anything important, especially resumes or legal documents.
I also assumed a free app could merge unlimited files, only to find out after the third document that it locked the feature behind a paywall. Now I always check what the free tier actually includes before relying on an app for something urgent.
And one time, I signed a document using an app that added a small watermark I hadn’t noticed, which made the whole thing look unprofessional when I sent it to a client. Always preview the final file before hitting send.
A Few Things I’d Tell a Friend
If you only need to sign things occasionally, don’t overthink it — Adobe Acrobat Reader or your phone’s built-in markup tool is enough.
If you deal with PDFs weekly, for school or work, something like Xodo or Foxit is worth the extra download because the merging and annotation tools save real time.
And if you’re constantly converting PDFs to Word or scanning paper documents, the Microsoft Office app quietly does a solid job without much fuss.
None of these apps are perfect. They all push you toward a subscription eventually, and that’s just how these companies make money. But knowing which free features are actually solid — and which ones are traps — makes a real difference when you’re stuck trying to get something done in ten minutes at a coffee shop, phone in hand, no printer in sight.
That rental agreement I mentioned at the start? Signed, sent, and done before my coffee even got cold. That’s really all I wanted from any of these apps in the first place.