Developer flashcards
that stick

82 interactive flashcard packs with real code examples. Open in your browser, study offline, print for your desk. No app needed.

Browse Packs Download Free Pack
82
Packs
1,640
Cards
32
Topics
100%
Offline
Who it's for

Built for developers at every stage

🔬

Security professionals

15 packs covering OWASP, pentesting, Active Directory, cloud security, forensics, and incident response. The most comprehensive cybersec flashcard suite available.

15 PACKS / 300 CARDS
💻

Career switchers

Interview prep bundle with DSA, system design, and behavioral frameworks. Plus full-stack coverage from HTML basics to Kubernetes.

INTERVIEW PREP + FULL STACK
⚡

Senior devs filling gaps

Picked up Go last month? Switching to Rust? Need a quick refresher on K8s networking? Grab just the packs you need.

32 TOPICS / LICENSE ONLY WHAT YOU NEED
How it works

Three steps to mastery

1

Open in your browser

Each pack is a standalone HTML file. No app, no login, no internet required. Works on any device.

2

Flip, study, quiz

Click cards to reveal answers with real code examples. Use quiz mode to test yourself. Filter by category.

3

Print for offline

Every pack includes a printable PDF — clean 2-column layout perfect for desk reference or commute study.

What's inside

Not your average flashcards

Real code examples

Production-quality snippets with syntax highlighting. Patterns you'll actually use at work.

Interactive quiz mode

Test yourself with built-in quiz. Track which cards you've mastered and which need practice.

Filter by category

Tag-based filtering in every pack. Jump to hooks, routing, deployment, auth — whatever you need.

Works offline forever

Pure HTML + CSS + JS. No server, no API, no tracking. Open the file and study.

14-pack security suite

The most comprehensive cybersec flashcard collection. OWASP, pentesting, AD, cloud security, forensics, IR.

Printable PDFs included

Every pack ships with a clean A4 PDF. Two-column layout. Print, fold, carry.

32 topics covered

Find your stack

Cybersecurity15 packs
Networking FundamentalsWeb App Security Pack 1Web App Security Pack 2ExploitationPrivilege EscalationActive Directory Pack 1Active Directory Pack 2Cloud Security Pack 1Cloud Security Pack 2Malware Analysis & ForensicsMobile & IoT SecurityOSINT & PasswordsOWASP Top 10Pentesting & Incident ResponseSandbox & Virtualization
AWS3 packs
Core Services (EC2, S3, IAM, VPC)Advanced (ECS, Lambda, CloudFormation)Security & Monitoring
React3 packs
Core Concepts & HooksPatterns & PerformanceServer Components & Advanced
TypeScript3 packs
Fundamentals & TypesGenerics & Utility TypesAdvanced Patterns
Next.js3 packs
App Router & RoutingData Fetching & CachingDeployment & Advanced
Python3 packs
Core ConceptsOOP & Data StructuresAsync, Testing & Stdlib
JavaScript3 packs
Core Concepts & ES6+Async & DOMPatterns & Advanced
Node.js3 packs
Core & ModulesExpress & MiddlewareStreams, Workers & Performance
SQL3 packs
Fundamentals & QueriesJoins, Subqueries & Window FunctionsOptimization & Administration
Go3 packs
FundamentalsConcurrency & ChannelsStandard Library & Testing
Rust3 packs
Ownership & FundamentalsLifetimes & TraitsError Handling & Async
Java3 packs
Core OOP & SyntaxCollections & GenericsStreams, Concurrency & Modern Java
PHP3 packs
Fundamentals & SyntaxOOP & NamespacesModern PHP & Frameworks
HTML3 packs
FoundationsForms & AdvancedAccessibility & Modern APIs
CSS3 packs
FundamentalsFlexbox & GridModern CSS & Responsive
Bootstrap3 packs
Grid & LayoutComponentsUtilities & Customization
Interview Prep3 packs
Data Structures & AlgorithmsSystem DesignBehavioral & Soft Skills
Docker2 packs
Fundamentals & ImagesCompose & Production
Kubernetes2 packs
Core Concepts & PodsNetworking & Scaling
Tailwind2 packs
Utilities & LayoutComponents & Customization
Testing2 packs
Unit Testing & TDDIntegration & E2E
React Native1 pack
Core Concepts & Navigation
Swift / iOS1 pack
SwiftUI & iOS Development
Kotlin / Android1 pack
Jetpack Compose & Android
Unity / C#1 pack
Game Dev Essentials
Godot / GDScript1 pack
Game Dev Essentials
Linux / SysAdmin1 pack
System Administration
Git1 pack
Version Control Essentials
Data Engineering1 pack
ETL, Spark & dbt
API Design1 pack
REST & GraphQL
CI/CD1 pack
Pipelines & Deployment
VS Code1 pack
Productivity & Shortcuts
Try it

See how CodeFlash cards work

Click any card to flip it

hooks
What is useState and how do you use it in React?
useState returns a [value, setter] pair. Call the setter to update state and trigger a re-render. Use functional updates when the new state depends on the previous value.
const [count, setCount] = useState(0); // Direct update setCount(5); // Functional update (depends on prev) setCount(prev => prev + 1);
injection
What is SQL injection and how do you prevent it?
Untrusted data sent as part of a SQL query. The attacker can read, modify, or delete data. Always use parameterized queries — never string concatenation.
# VULNERABLE query = f"SELECT * FROM users WHERE name = '{input}'" # SAFE — parameterized cursor.execute( "SELECT * FROM users WHERE name = %s", (user_input,) )
concurrency
How do goroutines and channels work in Go?
Goroutines are lightweight threads launched with the go keyword. Channels are typed conduits for communication between goroutines — they block until both sender and receiver are ready.
ch := make(chan string) go func() { ch <- "hello" // send }() msg := <-ch // receive (blocks until sent) fmt.Println(msg)
These are 3 of 1,640 cards. Each pack has 20 cards with filtering, quiz mode, and progress tracking.

Try the full experience

Download a complete pack for free — 20 interactive flashcards, quiz mode, filters, and a printable PDF. Pick any of three:

HTML FoundationsPython Core ConceptsOWASP Top 10
Pricing

One license, study forever

License a pack you want to own (downloadable, works offline), or subscribe to explore the full catalog (streaming, non-downloadable).

All-Access · Monthly
€24 /month
Stream the full catalog via the web app. Non-downloadable. Cancel anytime.
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BEST VALUE
All-Access · Annual
€149 /year
€12.41 / month equivalent — 1 month free. Streaming access to the full catalog; non-downloadable.
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Specialization bundles

Front End Engineer
€89
HTML, CSS, JavaScript, React, TypeScript, Next.js, Tailwind, and Bootstrap — the complete frontend stack.
23 packs · 460 cards · downloadable license + 12 mo updates
View BundleStore Opening Soon
Security Engineer
€69
OWASP, pentesting, AD attacks, cloud security, malware analysis, forensics, IR, OSINT, sandbox/virtualization, and more.
15 packs · 300 cards · downloadable license + 12 mo updates
View BundleStore Opening Soon
DevOps Engineer
€59
Docker, Kubernetes, AWS, Linux administration, Git workflows, and CI/CD pipeline patterns.
12 packs · 240 cards · downloadable license + 12 mo updates
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Back End Engineer
€59
Node.js, Python, SQL, Docker, Testing, and API Design — server-side patterns with real code.
12 packs · 240 cards · downloadable license + 12 mo updates
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Cloud / AWS Architect
€49
AWS core services, Docker, Kubernetes, and Linux — CLI commands and architecture patterns.
8 packs · 160 cards · downloadable license + 12 mo updates
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Data Engineer
€39
ETL/ELT, Apache Spark, dbt, SQL, Python, and Docker for data pipelines and warehousing.
6 packs · 120 cards · downloadable license + 12 mo updates
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Interview Prep
€39
Data structures & algorithms, system design patterns, and behavioral interview frameworks.
6 packs · 120 cards · downloadable license + 12 mo updates
View BundleStore Opening Soon
Mobile Developer
€39
React Native, Swift/SwiftUI, and Kotlin/Jetpack Compose — cross-platform and native.
6 packs · 120 cards · downloadable license + 12 mo updates
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Game Developer
€39
Unity/C# and Godot/GDScript — GameObjects, signals, physics, animation, AI patterns.
5 packs · 100 cards · downloadable license + 12 mo updates
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Individual Pack · License
€9
Any single topic — 20 interactive flashcards with code examples + printable PDF.
1 pack · 20 cards · downloadable license + 12 mo updates
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FAQ

Common questions

What format are the flashcards in?
Each pack is a standalone HTML file that opens in any web browser — Chrome, Firefox, Safari, Edge, on any device. No app install needed. Every pack also comes with a printable A4 PDF. The HTML files include interactive card flipping, quiz mode, category filters, and progress tracking — all running locally with zero dependencies.
Do I need an internet connection?
No. Once downloaded, the packs work completely offline. Pure HTML/CSS/JavaScript with no external API calls, no tracking, and no server dependencies. They'll work forever.
Can I try before buying?
Yes — three complete packs are free to download: HTML Foundations, Python Core Concepts, and OWASP Top 10. Each one is 20 interactive flashcards with quiz mode, filters, and a printable PDF. Experience the full product before you buy.
Are the code examples real and tested?
Yes. Every code snippet uses current syntax, real tool commands, and production patterns. The cybersecurity packs include actual tool commands (nmap, Burp Suite, Metasploit) with safe example targets. Code is validated for syntax correctness across all 1,640 cards.
What's your refund policy?
If you're not satisfied, contact us within 14 days for a full refund. No questions asked.
Do I get updates?
The All-Access Bundle includes lifetime updates — when we release new packs, you get them. Individual packs and bundles receive content updates but don't include new packs outside your purchase.