Honest pros, cons, and verdict on this language model tool
â Scores 72.7% on SWE-bench Verified, leading mid-tier coding benchmarks at launch
Starting Price
Free
Free Tier
Yes
Category
Language Model
Skill Level
Any
An advanced AI language model that delivers superior coding and reasoning capabilities with more precise instruction following. Offers both near-instant responses and extended thinking modes for deeper reasoning tasks.
Claude Sonnet 4 is a Language Model from Anthropic that delivers state-of-the-art coding and reasoning capabilities with hybrid instant and extended thinking modes, with pricing starting at $3 per million input tokens and $15 per million output tokens. It is built for developers, engineering teams, and enterprises that need a balanced, high-throughput model for production workloads.
Released in May 2025 as part of the Claude 4 family alongside Claude Opus 4, Sonnet 4 represents a significant upgrade over Claude Sonnet 3.7, scoring 72.7% on SWE-bench Verified â one of the highest publicly reported scores for a frontier coding model at launch. The model introduces hybrid reasoning, meaning users can toggle between near-instant responses for routine queries and an extended thinking mode that lets the model deliberate for longer on complex problems. It also gains the ability to use tools (such as web search) during extended thinking, alternating between reasoning steps and tool calls to improve answers. Anthropic has tightened instruction-following behavior, reduced reward-hacking shortcuts by 65% versus Sonnet 3.7 on agentic coding tasks, and added parallel tool use plus improved memory when developers grant file access.
per month
per month
Hybrid reasoning model that pushes the frontier for coding and AI agents, featuring a 1M context window and adaptive thinking for complex multi-step tasks.
Starting at See pricing
Learn more âClaude Sonnet 4 delivers on its promises as a language model tool. While it has some limitations, the benefits outweigh the drawbacks for most users in its target market.
An advanced AI language model that delivers superior coding and reasoning capabilities with more precise instruction following. Offers both near-instant responses and extended thinking modes for deeper reasoning tasks.
Yes, Claude Sonnet 4 is good for language model work. Users particularly appreciate scores 72.7% on swe-bench verified, leading mid-tier coding benchmarks at launch. However, keep in mind falls short of claude opus 4 on the hardest reasoning and research-grade coding tasks.
Yes, Claude Sonnet 4 offers a free tier. However, premium features unlock additional functionality for professional users.
Claude Sonnet 4 is best for Powering autonomous coding agents inside IDEs like Cursor, Windsurf, and GitHub Copilot, where reliable multi-step instruction following is critical and Building customer-facing chat products where you need a balance of low-latency responses and an optional 'deep think' escalation path. It's particularly useful for language model professionals who need hybrid instant and extended thinking modes.
Popular Claude Sonnet 4 alternatives include Claude Opus 4.7. Each has different strengths, so compare features and pricing to find the best fit.
Last verified March 2026