Core Java courses can help you learn object-oriented programming, exception handling, multithreading, and Java Collections. You can build skills in writing efficient algorithms, debugging code, and developing user interfaces. Many courses introduce tools like Eclipse and IntelliJ IDEA, which are commonly used for coding and testing Java applications, along with frameworks such as Spring and Hibernate that facilitate web development and database management.

Codio
Skills you'll gain: Algorithms, C++ (Programming Language), Data Structures, Computer Programming, Computational Thinking, Technical Design
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Restful API, Android Development, Kotlin, API Design, Android Studio, Mobile Development, Database Management, Data Persistence, Databases, JSON, Web Applications, SQL
Intermediate · Course · 1 - 3 Months
Skills you'll gain: Angular, Test Driven Development (TDD), Web Components, HTML and CSS, Web Development, Software Testing, Cascading Style Sheets (CSS), Front-End Web Development, Development Environment, UI Components, Javascript, Data Persistence, Event-Driven Programming, Data Management, Command-Line Interface
Intermediate · Course · 1 - 4 Weeks

O.P. Jindal Global University
Skills you'll gain: Computational Logic, Classification Algorithms, Natural Language Processing, Artificial Intelligence, Applied Machine Learning, Machine Learning, Business Strategy, Unsupervised Learning, Decision Support Systems, Strategic Decision-Making, Decision Tree Learning, Bayesian Statistics, Complex Problem Solving, Probability & Statistics, Information Architecture, Algorithms
Build toward a degree
Mixed · Course · 3 - 6 Months

Scrimba
Skills you'll gain: Claude Code, Vibe coding, Anthropic Claude, Model Context Protocol, Application Development, Command-Line Interface, Application Design, Programming Principles, Generative AI, Automation, Generative AI Agents, Image Analysis, Artificial Intelligence and Machine Learning (AI/ML), Agentic systems
Intermediate · Course · 1 - 4 Weeks

Simplilearn
Skills you'll gain: Apache Maven, Build Tools, CI/CD, Software Configuration Management, Version Control, Java, Software Versioning, Configuration Management, Package and Software Management, Mac OS, Software Installation
Beginner · Course · 1 - 4 Weeks

Scrimba
Skills you'll gain: JSON, Restful API, Web Applications, Application Programming Interface (API), Responsive Web Design, Cascading Style Sheets (CSS), Event-Driven Programming, HTML and CSS, Javascript, Back-End Web Development, Frontend Integration, Web Development, Web Services, Real Time Data, Web Development Tools, Game Design, Hypertext Markup Language (HTML), Servers, Software Development
Intermediate · Specialization · 1 - 4 Weeks

Skills you'll gain: Exploratory Data Analysis, Statistical Modeling, Regression Analysis, Data Visualization, Model Evaluation, Data Analysis, Statistical Methods, Scatter Plots, R Programming, Statistical Analysis, Plot (Graphics), R (Software), Ggplot2
Beginner · Guided Project · Less Than 2 Hours

University of California, Davis
Skills you'll gain: Chemical Engineering, Hazard Analysis, Safety Assurance, Process Engineering, Engineering Analysis, Environmental Engineering, Engineering Calculations, Mathematical Modeling, Applied Mathematics
Mixed · Course · 1 - 4 Weeks

University of London
Skills you'll gain: User Experience Design, Wireframing, Application Design, Technical Communication, Prototyping, Web Development, User Research, Usability Testing, Responsive Web Design, Version Control, Brainstorming, Project Planning, Application Programming Interface (API), Javascript, MongoDB
Mixed · Course · 1 - 3 Months

Coursera
Skills you'll gain: TypeScript, Javascript, React.js, Debugging, Integrated Development Environments, Web Development Tools
Intermediate · Guided Project · Less Than 2 Hours

Coursera
Skills you'll gain: R Programming, Arithmetic, Statistical Programming, Development Environment, Programming Principles, Data Import/Export
Beginner · Guided Project · Less Than 2 Hours