Intelligence index
Outperforms 56% of compared models
Claude Sonnet 4.5
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with improvements across system design, code security, and specification adherence. The model is designed for extended autonomous operation, maintaining task continuity across sessions and providing fact-based progress tracking.
Sonnet 4.5 also introduces stronger agentic capabilities, including improved tool orchestration, speculative parallel execution, and more efficient context and memory management. With enhanced context tracking and awareness of token usage across tool calls, it is particularly well-suited for multi-context and long-running workflows. Use cases span software engineering, cybersecurity, financial analysis, research agents, and other domains requiring sustained reasoning and tool use.
- Input / output price
- $3/$15per 1M tokens
- Context
- 1.0M
- Released
- 2025-09-29
Pricing
Artificial Analysis
Explore rankingsCoding index
Outperforms 57% of compared models
Agentic index
Outperforms 47% of compared models
Design Arena
Elo scores and win rates across design and agent tasks.
Category performance
1,000-1,500 EloModel Arena
Asciiart
1202Elo
Win rate 56.1%
SVG
1113Elo
Win rate 52.2%
3D
1155Elo
Win rate 51%
Code Categories
1181Elo
Win rate 51.5%
Game Development
1166Elo
Win rate 51.1%
UI Component
1167Elo
Win rate 49.4%
Website
1188Elo
Win rate 51.8%
Data Visualization
1167Elo
Win rate 47.4%
Agent Arena
Mobile Apps
1137Elo
Win rate 52.9%
Fullstack
1050Elo
Win rate 43.7%
Webapps
1059Elo
Win rate 43.2%
Related Models
Claude Opus 5.5
anthropicClaude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5. It is particularly strong at multi-step changes in large codebases, code review and bug finding, financial and scientific analysis, and reading dense charts, diagrams, and screenshots, and it is more careful than its predecessor about only stating figures and citing sources it can back up. The model completes comparable tasks in fewer steps and with fewer tokens than Opus 5, and reports on its work in plainer language, with clear updates on what it did, what it found, and what it needs from the user. Thinking is always adaptive, so effort is the main lever for trading off depth, latency, and cost, and lower effort settings remain effective for latency-sensitive workloads.
- Context
- 1.0M
- Max output
- 128K
- Released
- 2026-09-22
- Input
- $4/M
- Output
- $20/M
- Cache read
- $0.2/M
Claude Sonnet 5.5
anthropicClaude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade. It is especially strong at building features, fixing bugs, and producing polished documents, slides, and spreadsheets, and it writes and communicates more clearly than its predecessor. Thinking is always on, so effort is the main lever for trading off depth, latency, and cost, and lower effort settings keep it responsive for everyday agentic loops.
- Context
- 1.0M
- Max output
- 128K
- Released
- 2026-09-28
- Input
- $2/M
- Output
- $10/M
- Cache read
- $0.1/M
Claude Fable 5.1
anthropicClaude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors, front-end and visual code generation, and finance and analysis tasks in particular. It also tends to be more concise than Fable 5 in its plans and summaries. We recommend testing it as a direct upgrade wherever you use Fable 5 today, and alongside Opus 5 on reasoning-heavy tasks.
- Context
- 1.0M
- Max output
- 128K
- Released
- 2026-09-01
- Input
- $10/M
- Output
- $50/M
- Cache read
- $0.25/M