Flutter Security Guidelines

Learn how to
build secure
Flutter apps

Your ultimate guide to securing your Flutter apps, covering everything from data encryption to network security, authentication, and how to prevent reverse engineering your code.

Is your Flutter app really secure?

Zoran Juric

Hey there. I'm Zoran Juric. I build mobile apps. For a long time, I've fixed security problems others made. Or, let's be honest, problems I made myself early on.

When I started with Flutter, security seemed simple: Check some boxes. API via HTTPS? Done. Obfuscation? Included. I figured that was enough. However, security was often treated like just another task. Pretty standard stuff, right?

Well, I was wrong. Thinking that security is just a checklist is a bad idea. Attackers look for easy ways in. They don't care about your good intentions. They test if your app is actually secure.

Flutter apps are great. They look good and run fast. But they have hidden spots where data can leak if you're not careful. I learned this the hard way. I spent days reverse-engineering apps. I studied Firebase and Supabase rules closely. I broke into insecure storage on devices. Weak APIs were explored to find holes. All this was done to learn how to build safer apps.

This book shares what I learned. It's the guide I wish I had years ago. You won't find dry theory here. It's full of real tips for your Flutter projects. We'll look at stopping data leaks. We'll see how to hide secret keys properly. You'll learn to make apps that stand up to common attacks.

Want to build apps people can trust? This guide is for you. It helps developers like you make apps that keep user data safe.

What's inside?

What's inside?

This book has eight chapters, all of which share one goal: to make your Flutter app tougher for others to break into.

The book is written using Notion*, which makes it easy to use. You can browse it like a website. Need some code? Just copy and paste it. Searching for a specific topic is also quick.

The OWASP MASVS standards guide the content. These are well-known rules for mobile app security. Each chapter covers one standard. We look at topics like cryptography and keeping storage secure. We also cover defenses against reverse engineering and protecting user data privacy.

I wrote this for Flutter developers working on real projects. You won't find useless info here. Forget long talks about theory. Instead, you get clear security steps. You get examples. You get ways to test your app. This is stuff you can actually put to work.

You don't have to read this book from start to finish. Feel free to jump around. Each chapter works on its own. Need help making API calls safer? Go straight to that chapter. Want to lock down local storage? Find the section you need. It's all good.

Ever searched "how to secure a Flutter app"? Did you get lost in old Stack Overflow answers? We've all been there. This book gives you the real answers you need today.

* PDF and e-pub versions are planned for later release if you prefer those formats.

Table of Contents

Early Access

The first chapter is available immediately.
The remaining chapters will be released regularly over the coming months.

  1. 1. Data Storage

    Available
    1. Data Storage in Flutter Web Apps
    2. Compliance with OWASP Standards
  2. 2. Cryptrography

    Coming soon
  3. 3. Authentication and Authorization

    Coming soon
  4. 4. Network Communication

    Coming soon
  5. 5. Platform Interaction

    Coming soon
  6. 6. Code Quality

    Coming soon
  7. 7. Resilience to Reverse Engineering and Tempering

    Coming soon
  8. 8. User Data Privacy

    Coming soon

Resources

Need help implementing security ideas? I've included extra resources.

These resources help you apply the book's lessons. They are useful if you are learning, building, or trying to break your app safely.

  1. Example Projects

    All the sample code is open source, and is hosted on GitHub. You get demo Flutter apps for each chapter. You also get Frida (pentesting) scripts. Use them to try the techniques yourself.

  2. Curated Directory

    This list keeps growing. It has the best links, tools, and documents for Flutter security. Only useful stuff is included.

  3. Code Reviews and Audits

    See how security is approached in real-world Flutter apps. Take a look at actual code and find out how to avoid common mistakes with better coding habits.

Get Early Access & Free Updates

Want to read Flutter Security Guidelines before anyone else? Good news! The book is now open for early access. You can join the waitlist today. Be one of the first people to read chapters as they get finished.

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