Cline is an open-source AI coding assistant for VS Code that features dual Plan/Act modes, terminal execution capabilities, and the Model Context Protocol (MCP) for custom tool creation. It serves as a fully collaborative AI partner for developers.

How is Cline different from GitHub Copilot?

Cline is open-source and offers unique features like Plan/Act modes for structured development, terminal command execution, browser automation for testing, and the Model Context Protocol (MCP) for creating custom development tools.

What programming languages does Cline support?

Cline supports all major programming languages and frameworks through its AI models and can execute terminal commands, edit files, and automate browser testing across different technology stacks.

Written by

Nick Baumann

Published on

June 26, 2025

Cline v3.18: Optimized Claude 4

Hello Cline community 🫡

Optimizations for Claude 4

We've invested significant effort in optimizing Cline with the Claude 4 family of models. We now recommend the Claude 4 models, particularly Sonnet, as the default for the best results in Cline.

The most critical improvement is in the reliability of our diff-based file editing. In production, we've observed the failure rate for complex diff edits drop from 10% down to just 6%.

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These gains are even more pronounced in our internal "hard mode" benchmarks, which test Cline against particularly challenging code modification tasks. On these tests, the success rate for diff edits jumped from 64.4% to an impressive 84.3%.

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Other Improvements

This release also includes a few other notable fixes:

We've resolved a race condition that could occur when switching between Plan and Act modes.
The robustness of our search and replace parsing has been improved to handle more edge cases.
The default and recommended model has been officially updated to Claude 4 Sonnet.

Get Started Today

Cline v3.18 is available now. Update wherever you use Cline and let us know what you think!

-Nick 🫡