Cline Review 2026: Best Free AI Coding Extension for VS Code
Key Takeaways:
- • 100% free and open-source — Cline itself costs nothing, but you pay $5-22/month for API keys (Claude, GPT, or Gemini)
- • Multi-model flexibility is the killer feature — switch between Claude for reasoning, GPT-4 for speed, and Gemini Flash for cheap bulk tasks
- • No inline autocomplete — unlike Copilot, Cline requires explicit chat prompts; slower for small edits but more powerful for multi-file refactoring
- • Rating: 8.5/10 — excellent for power users who want control and transparency, but not beginner-friendly
After two months of daily use on production projects, I've found Cline to be the most flexible AI coding assistant I've tested—but it's not for everyone. If you want a polished, plug-and-play experience, stick with Cursor or Copilot. If you value control, transparency, and don't mind managing API keys, Cline might be your best coding companion.
This review covers real-world testing across TypeScript/React projects, Python scripts, and even some Rust experiments. I'll share what works, what doesn't, and who should actually use this tool.
What Is Cline?
Cline is an open-source AI coding assistant built as a VS Code extension. Unlike autocomplete-focused tools like GitHub Copilot, Cline operates as an agentic assistant—it can read your entire codebase, edit multiple files, run terminal commands, and even control a browser for testing.
The key difference? You bring your own AI model. Cline supports:
- Claude (Anthropic API) — best for complex reasoning
- GPT-4/GPT-4 Turbo (OpenAI API) — fast and reliable
- Gemini 2.0 (Google AI) — budget-friendly option
- Local models via Ollama — completely offline
This flexibility is Cline's superpower. Switch models based on task complexity, budget, or privacy requirements. No vendor lock-in.
How We Tested
I ran Cline through ~60 hours of real development work over 8 weeks:
- Projects: Next.js 14 web app, Python data pipeline, Rust CLI tool
- Models tested: Claude Sonnet 4.5, GPT-4 Turbo, Gemini 2.0 Flash
- Tasks: Feature implementation, bug fixing, refactoring, writing tests
- Cost tracking: Monitored API usage via provider dashboards
My baseline comparison was 3 months prior experience with Cursor Pro and 6 months with GitHub Copilot. I tracked completion time, code quality, and total monthly costs.
Key Features That Actually Matter
1. Multi-Model Support
The ability to switch between Claude, GPT, and Gemini based on the task is genuinely useful. I use Claude Sonnet for architecture decisions, GPT-4 Turbo for speed, and Gemini Flash for repetitive tasks to save costs.
2. File System Access
Cline can read, create, edit, and delete files across your entire project. It asks for permission before making changes, showing you a diff preview. This beats manually copying code suggestions from ChatGPT.
3. Terminal Integration
Run commands directly from chat: install packages, run tests, start dev servers. Cline can debug failing tests by reading error output and iterating on fixes automatically.
4. Browser Automation (Experimental)
Cline can control a browser to test your web app, click buttons, fill forms, and verify behavior. It's rough around the edges but surprisingly effective for simple E2E testing.
5. MCP (Model Context Protocol) Support
Connect external tools like databases, APIs, or custom scripts. I built a simple MCP server to let Cline query our Postgres database directly—game changer for data-driven features.
Pricing: It's Free (But Not Really)
Cline itself is 100% free and open-source. No subscriptions, no trials, no credit card.
But you need to pay for API access to your chosen AI model:
My Monthly Costs (Moderate Use)
- Claude Sonnet 4.5: ~$12/month (heavy reasoning tasks)
- GPT-4 Turbo: ~$8/month (general coding)
- Gemini 2.0 Flash: ~$2/month (boilerplate/tests)
- Total: ~$22/month
Compare that to Cursor Pro ($20/month) or GitHub Copilot ($10/month). Cline costs more if you use premium models heavily, but you get full control and transparency.
Light users (1-2 hours/day) can stay under $10/month by sticking to Gemini Flash or local Ollama models.
What We Liked
- ✓No Vendor Lock-In: Switch AI providers anytime. Use Gemini for cheap tasks, Claude for hard problems.
- ✓Full Transparency: See exactly what Cline is doing, every API call, every file change. Open-source means no black boxes.
- ✓Privacy Control: Use local Ollama models for sensitive codebases. No code leaves your machine.
- ✓Active Development: Weekly updates, responsive maintainers, growing community. Issues get fixed fast.
- ✓MCP Extensibility: Build custom integrations for your workflow. I connected Slack notifications, Jira tickets, and database queries.
What We Didn't Like (Honest Take)
- ✗Setup Complexity: Managing API keys for multiple providers is tedious. You need to understand rate limits, pricing tiers, and token counting. Not beginner-friendly.
- ✗No Inline Autocomplete: Cline doesn't have tab-completion like Copilot. You need to explicitly ask for code in chat. Slower for small edits.
- ✗Token Costs Add Up: Large refactoring tasks can burn through $5-10 in API costs in a single session if you're not careful. Cursor's flat $20/month feels safer.
- ✗UI Polish: The interface is functional but clunky. Cursor's chat UI, diff viewer, and inline edits feel more refined.
- ✗Browser Automation Bugs: The Playwright integration crashes occasionally, especially on complex SPAs. Needs more stabilization.
Cline vs Cursor vs GitHub Copilot
| Feature | Cline | Cursor | Copilot |
|---|---|---|---|
| Pricing | Free + API costs ($5-20/mo) | $20/month | $10/month |
| AI Models | Claude, GPT, Gemini, Ollama | GPT-4, Claude (limited) | GPT-4 only |
| Autocomplete | No | Yes (excellent) | Yes (best-in-class) |
| Agentic Features | File edits, terminal, browser | File edits, terminal | Chat only |
| Open Source | Yes | No | No |
| Privacy | Full control (local models) | Privacy mode available | Code sent to OpenAI |
| Ease of Setup | Complex (API keys) | Simple (email login) | Simple (GitHub login) |
Cline
Free open-source AI coding assistant for VS Code — bring your own API key
Who Should Use Cline?
Perfect For:
- Developers who want full control over their AI workflow
- Teams with privacy/compliance requirements (use local models)
- Budget-conscious users willing to optimize API usage
- Open-source enthusiasts who value transparency
- Power users who want to build custom MCP integrations
Not Ideal For:
- Beginners who want plug-and-play setup
- Developers who rely heavily on autocomplete (stick with Copilot)
- Teams who need predictable monthly costs
- Users who prefer polished, commercial UX
If you're comfortable managing API keys and want the flexibility to choose your AI model based on task and budget, Cline is unbeatable. If you want a smooth, no-hassle experience, pay for Cursor or Copilot.
Related Reading
Frequently Asked Questions
Is Cline really free?
Yes, Cline is completely free and open-source. However, you need to provide your own API keys (Claude, GPT, or Gemini), which cost around $5-15/month for moderate use depending on your model choice and usage patterns.
How does Cline compare to GitHub Copilot?
Cline is an agentic coding assistant that can edit files and run commands, while Copilot focuses on inline code completion. Cline gives you more control and supports multiple AI models, but Copilot has better tab-completion and is more polished for autocomplete workflows.
Can I use Cline with Claude/GPT/Gemini?
Yes, Cline supports all major AI models including Claude (via Anthropic API), GPT-4 (via OpenAI API), and Gemini (via Google AI). You can switch between models based on your task and budget.
What are the main downsides of Cline?
Setup complexity (managing API keys), no built-in tab completion like Copilot, token costs can add up quickly for large projects, and the UI is less polished than commercial tools like Cursor. It also requires you to understand API pricing to control costs.
Final Verdict
Cline is the best free AI coding assistant in 2026—if you're willing to trade convenience for control. The multi-model support, open-source nature, and agentic capabilities make it incredibly powerful for experienced developers.
But it's not a Copilot replacement. You'll miss autocomplete, spend time managing API keys, and occasionally deal with rough edges. For me, the flexibility is worth it. For many, paying $20/month for Cursor's polish makes more sense.
Rating: 8.5/10 — Excellent tool for power users, not for beginners.