Best AI Coding Assistant for IntelliJ IDEA in 2025

Why IntelliJ Developers Need an AI Coding Assistant

IntelliJ IDEA is already one of the most powerful IDEs on the market, packed with intelligent code completion, refactoring tools, and deep language support. So why add an AI coding assistant on top of it?

The answer is simple: modern AI assistants go far beyond what traditional IDE tooling can offer. They understand context across entire codebases, generate boilerplate code in seconds, explain complex logic in plain English, write and fix unit tests, and even suggest architectural improvements. For developers working in Java, Kotlin, Scala, or any of the other languages IntelliJ supports, the right AI plugin can dramatically reduce friction and accelerate delivery.

We've tested and compared the leading options available today so you can find the Best-ai-writing-tools-reddit">Best-ai-writing-tools-free">Best-ai-writing-tools-for-novels">Best-ai-writing-tools-for-students">Best AI coding assistant for IntelliJ that matches your workflow, team size, and budget.

What to Look for in an IntelliJ AI Coding Assistant

Before diving into our top picks, let's establish the criteria we used to evaluate each tool:

IntelliJ plugin availability: Does it have a native, well-maintained plugin on the JetBrains Marketplace?
Code completion quality: How accurate and context-aware are the inline suggestions?
Chat interface: Can you ask questions, request refactors, or get explanations without leaving the IDE?
Codebase understanding: Does it index your local project for deeper, more relevant suggestions?
Language support: Strong support for Java and Kotlin is essential; broader coverage is a bonus.
Privacy and security: Does it send your code to external servers? Are there enterprise-grade controls?
Pricing: Is there a free tier? What does the paid plan include?

With those criteria in mind, here are the best options available right now.

Top AI Coding Assistants for IntelliJ IDEA

1. GitHub Copilot

GitHub Copilot is the most widely adopted AI coding assistant in the world, and its IntelliJ plugin is mature, fast, and reliable. Powered by OpenAI's Codex models and now integrating GPT-4-class capabilities, Copilot offers inline ghost-text completions that feel remarkably natural when working in Java or Kotlin projects.

The Copilot Chat feature, available directly in IntelliJ, lets you highlight code and ask questions like "What does this method do?" or "Refactor this to use streams." It also supports slash commands for quick actions like /fix, /tests, and /explain.

Pros: - Excellent inline completion quality, especially for Java and Kotlin - Mature IntelliJ plugin with frequent updates - Copilot Chat deeply integrated into the IDE - Strong ecosystem and community support - Enterprise plans with IP indemnity and privacy controls

Cons: - No meaningful free tier (only a limited trial) - Suggestions can sometimes be outdated or miss project-specific conventions - Requires a GitHub account

Pricing: $10/month for individuals, $19/user/month for Business, $39/user/month for Enterprise.

2. JetBrains AI Assistant

If you want an AI tool that feels truly native to IntelliJ, JetBrains AI Assistant is the obvious choice. Built directly by the team behind IntelliJ IDEA, this assistant is deeply integrated into the IDE's core features — it understands your project structure, run configurations, VCS history, and even your commit messages.

JetBrains AI Assistant uses a combination of cloud-based LLMs (including OpenAI and custom models) and understands JetBrains-specific context like inspections, intentions, and project settings. The "AI Actions" feature lets you right-click on any code and ask for explanations, documentation, or refactoring suggestions through a context menu.

It also handles commit message generation, test generation, and inline documentation — all of which feel polished and purpose-built for IntelliJ's environment.

Pros: - Deepest IntelliJ integration of any tool on this list - Understands IDE-specific context (inspections, VCS, project structure) - No separate plugin required — built into recent IntelliJ versions - Excellent commit message and documentation generation - No third-party data sharing concerns for JetBrains-hosted features

Cons: - Requires a paid JetBrains AI subscription on top of your IDE license - Chat quality for complex architectural questions can lag behind Copilot or Cursor - Newer product, so some features are still maturing

Pricing: JetBrains AI subscription starts at approximately $10/month (bundled discounts available with All Products Pack).

3. Tabnine

Tabnine has been around longer than most AI coding tools, and it's earned a loyal following among developers who prioritize privacy and on-premise deployment. Its IntelliJ plugin is one of the most downloaded on the JetBrains Marketplace.

What sets Tabnine apart is its ability to run entirely on your local machine or on a private server — meaning your proprietary code never leaves your infrastructure. For enterprise teams working with sensitive codebases, this is a significant differentiator. Tabnine also offers a team learning feature where the AI model can be fine-tuned on your team's specific codebase and coding conventions.

Pros: - Strong privacy controls with local and private server deployment options - Personalized AI that can learn from your team's codebase - Good free tier with basic completions - Long track record and proven reliability in enterprise environments - Supports a wide range of languages

Cons: - Completion quality not quite at par with Copilot for complex logic - Chat features are less polished than competitors - Local model performance depends heavily on your machine's hardware

Pricing: Free tier available; Pro plan at $12/month; Enterprise pricing on request.

4. Codeium (Now Windsurf)

Codeium — now rebranded as part of the Windsurf ecosystem — offers one of the best free tiers of any AI coding assistant, making it a top choice for individual developers and students who want powerful completions without a monthly bill.

Its IntelliJ plugin provides fast inline completions, a chat interface, and what Codeium calls "Supercomplete" — a feature that understands multi-line intent rather than just predicting the next token. The tool also indexes your local repository to make suggestions that are aware of your project's classes, methods, and patterns.

For developers exploring AI tools for the first time, Codeium/Windsurf is an excellent starting point. You can try it through the links in this article to see how it performs in your specific IntelliJ workflow before committing to a paid solution.

Pros: - Generous free tier with no usage caps - Fast, low-latency completions in IntelliJ - Codebase indexing for context-aware suggestions - Supports 70+ programming languages - No telemetry on free plan for individual users

Cons: - Enterprise features and fine-tuning are limited compared to Tabnine - Chat interface, while functional, is less sophisticated than Copilot Chat - Rebranding to Windsurf has caused some confusion around product roadmap

Pricing: Free for individuals; Teams plan at $12/user/month; Enterprise pricing available.

5. AWS CodeWhisperer (Amazon Q Developer)

Now rebranded as Amazon Q Developer, AWS's AI coding assistant has grown significantly since its initial release. It offers strong support for Java (particularly useful if you're building AWS-based backend systems) and includes security scanning as a built-in feature — something most competitors charge extra for or don't offer at all.

The IntelliJ plugin integrates well and supports multi-line completions, a chat panel, and reference tracking (it tells you when a suggestion is inspired by open-source code and what license applies). For teams already invested in the AWS ecosystem, Amazon Q Developer is a natural fit.

Pros: - Free tier includes 50 security scans per month - Excellent for AWS-specific Java development - Reference tracker keeps license compliance transparent - Good multi-line completion quality for Java - Strong enterprise features for AWS customers

Cons: - Less useful if you're not in the AWS ecosystem - Chat and explanation features aren't as refined as Copilot or JetBrains AI - Some users report the plugin can be heavier on IDE resources

Pricing: Free tier available; Pro plan at $19/user/month.

6. Sourcegraph Cody

Sourcegraph Cody takes a different approach from most tools on this list. Rather than focusing purely on completions, Cody is built around codebase-aware chat — it can search and understand your entire repository (and even multiple repositories) to answer complex questions about your code.

Its IntelliJ plugin lets you ask questions like "Where is this interface implemented across our monorepo?" or "Explain the data flow in this service." For large teams working on complex, sprawling codebases, this kind of deep search-augmented AI is genuinely powerful.

Pros: - Exceptional codebase understanding across large and multi-repo projects - Powered by multiple LLMs (Claude, GPT-4, Gemini) — user can choose - Strong for code navigation and architectural questions - Self-hosted deployment option available - Good free tier for individual developers

Cons: - Inline completion quality is secondary to chat capabilities - Setup can be more complex, especially for the self-hosted version - Better suited to larger teams than solo developers

Pricing: Free for individuals; Pro at $9/month; Enterprise pricing on request.

Comparison Table: Best AI Coding Assistants for IntelliJ

Tool	Free Tier	IntelliJ Plugin	Inline Completion	Chat	Local/Private Deployment	Best For
GitHub Copilot	Limited trial	✅ Excellent	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐	❌	Most developers
JetBrains AI	❌	✅ Native	⭐⭐⭐⭐	⭐⭐⭐⭐	❌	IntelliJ power users
Tabnine	✅ Basic	✅ Mature	⭐⭐⭐⭐	⭐⭐⭐	✅ Yes	Enterprise / privacy-first
Codeium/Windsurf	✅ Generous	✅ Good	⭐⭐⭐⭐	⭐⭐⭐	❌	Budget-conscious devs
Amazon Q Developer	✅ With scans	✅ Good	⭐⭐⭐⭐	⭐⭐⭐	❌	AWS-focused teams
Sourcegraph Cody	✅ Good	✅ Good	⭐⭐⭐	⭐⭐⭐⭐⭐	✅ Yes	Large/complex codebases

How to Install AI Plugins in IntelliJ IDEA

Installing any of these tools is straightforward:

Open IntelliJ IDEA and navigate to Settings → Plugins
Click on the Marketplace tab
Search for the tool by name (e.g., "GitHub Copilot", "Tabnine", "Codeium")
Click Install and restart the IDE when prompted
Follow the authentication steps specific to each tool

Most tools will also guide you through setup on their official websites, where you can find trial links and documentation. We recommend checking each tool's official page — accessible through the links mentioned throughout this article — to get the latest installation instructions.

Use Cases: Which Tool Fits Your Workflow?

For Solo Java/Kotlin Developers

GitHub Copilot or Codeium are the best starting points. Copilot has the edge in raw completion quality, while Codeium's free tier makes it easy to experiment without any financial commitment.

For Teams in Enterprises with Strict Security Requirements

Tabnine is the clear winner here, thanks to its private deployment options and fine-tuning capabilities. If your team works in a regulated industry and can't have source code leaving your infrastructure, Tabnine is purpose-built for that need.

For Developers Deep in the JetBrains Ecosystem

JetBrains AI Assistant offers an unmatched level of integration. Features like AI-generated commit messages, context-aware refactoring suggestions tied to IntelliJ inspections, and seamless IDE actions make it feel like a natural extension of the tool you already know.

For AWS-Heavy Backend Teams

Amazon Q Developer is worth serious consideration, especially for teams building Java microservices on AWS Lambda, Spring Boot on EC2, or anything touching the AWS SDK heavily.

For Large Engineering Teams Managing Complex Codebases

Sourcegraph Cody shines when your primary challenge is understanding and navigating large or multi-repo codebases rather than just generating boilerplate. Its chat capabilities, backed by multiple LLM choices, are genuinely impressive for architectural exploration.

AI Coding Assistants vs. Traditional IntelliJ Features

It's worth noting that IntelliJ's built-in features — like live templates, postfix completions, and code inspections — already solve many common pain points. AI assistants layer on top of these rather than replacing them.

The biggest value-add from AI tools comes in three areas that traditional IDE features don't address well:

Natural language interaction: Asking "why is this code slow?" or "write a test for this edge case" in plain English
Cross-file and cross-project context: Understanding how your code fits into the broader system
First-draft generation: Scaffolding new classes, service layers, or API endpoints from a high-level description

If you're comparing your options across IDEs, our best AI coding assistant for VS Code article covers how these same tools perform in Microsoft's editor — useful if you work across multiple environments.

We've also covered the best AI coding assistants broadly in 2025 and the best free AI coding assistants if budget is your primary concern.

Privacy Considerations for IntelliJ AI Plugins

One concern we hear frequently from enterprise developers is: "Is my code being sent to external servers?"

The short answer is: it depends on the tool and how you configure it.

GitHub Copilot Business/Enterprise: Offers options to disable code snippet retention and telemetry
Tabnine Enterprise: Can run entirely on-premise with no external data transmission
JetBrains AI: JetBrains has privacy commitments around data handling, but cloud features do involve server-side processing
Amazon Q Developer: Subject to AWS's data privacy policies; Enterprise can configure VPC endpoints for isolation
Codeium/Windsurf: Claims no training on individual user code; enterprise plans add further controls

Always review the privacy documentation for any tool before deploying it on a team working with proprietary or regulated code.

Our Verdict

After extensive testing across a range of IntelliJ IDEA projects — from Spring Boot REST APIs to Android Kotlin apps — here's our recommendation:

🥇 Best Overall: GitHub Copilot

For most IntelliJ developers, GitHub Copilot delivers the best combination of completion quality, chat capabilities, and plugin reliability. The investment is justified by the sheer productivity gains, particularly for developers spending significant time in Java or Kotlin codebases.

🥈 Best Native Integration: JetBrains AI Assistant

If you're a heavy IntelliJ user who values a seamless, everything-in-one experience and doesn't mind paying for an add-on subscription, JetBrains AI Assistant is worth the cost. The IDE-aware features are genuinely superior to anything a third-party plugin can offer.

🥉 Best Free Option: Codeium (Windsurf)

For developers who want to get started with AI-assisted coding without spending money, Codeium's free tier is the most generous and capable on the market. It's an excellent bridge to a paid solution once you're ready to invest.

Best for Enterprise Privacy: Tabnine

Teams that need private deployment and fine-tuning on proprietary codebases should evaluate Tabnine seriously. No other tool on this list matches its flexibility for security-sensitive environments.

The good news is that most of these tools offer free trials or free tiers — you can explore them through the links throughout this article before committing. Start with one that fits your immediate use case, spend two weeks using it seriously, and let the productivity data speak for itself. The right AI coding assistant won't just make you faster; it will change how you think about writing code entirely.