Best LLM for AI agents (2026)
Which model holds up in long-horizon, tool-calling agent loops?
Rebuilt from live model data · August 3, 2026
How we ranked
Ranked by Artificial Analysis Agentic Index; models without tool-calling support are excluded.
Top 3 for ai agents
- 1
Claude Opus 5
Agentic index: 55.3 $5.00 in / $25.00 out per 1M 1M context 5 providersClaude Opus 5 is Anthropic’s flagship model for demanding reasoning, coding, and long-horizon agentic work. It is particularly strong at end-to-end software tasks, code review and bug finding, visual analysis...
Vision Tool calling Reasoning Released Jul 24, 2026 - 2
GPT-5.6 Sol
Agentic index: 54.0 $5.00 in / $30.00 out per 1M 1.1M context 2 providersGPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series. It is suited for complex reasoning, coding, and agentic workflows, and is particularly strong at command-line and multi-step coding tasks...
Vision Tool calling Reasoning Released Jul 9, 2026 - 3
Claude Fable 5
Agentic index: 52.8 $10.00 in / $50.00 out per 1M 1M context 4 providersClaude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding. It supports text, image, and file inputs with text output, with reasoning support and...
Vision Tool calling Reasoning Released Jun 9, 2026
Full ranking
| # | Model | Agentic index | Output / 1M | Context | Providers | Weights |
|---|---|---|---|---|---|---|
| 1 | Claude Opus 5 | 55.3 | $25.00 | 1M | 5 | Closed |
| 2 | GPT-5.6 Sol | 54.0 | $30.00 | 1.1M | 2 | Closed |
| 3 | Claude Fable 5 | 52.8 | $50.00 | 1M | 4 | Closed |
| 4 | Kimi K3 | 50.1 | $15.00 | 1.0M | 6 | Open |
| 5 | GPT-5.6 Terra | 47.4 | $7.50 | 1.1M | 2 | Closed |
| 6 | Claude Opus 4.8 | 47.2 | $25.00 | 1M | 4 | Closed |
| 7 | Claude Sonnet 5 | 46.7 | $10.00 | 1M | 4 | Closed |
| 8 | Grok 4.5 | 45.7 | $6.00 | 500K | 1 | Closed |
| 9 | GPT-5.6 Luna | 45.6 | $3.00 | 1.1M | 2 | Closed |
| 10 | GPT-5.5 | 44.9 | $30.00 | 1.1M | 2 | Closed |
| 11 | Claude Opus 4.7 | 44.4 | $25.00 | 1M | 4 | Closed |
| 12 | GLM 5.2 | 43.1 | $2.33 | 1.0M | 29 | Open |
FAQ
Which model holds up in long-horizon, tool-calling agent loops?
Claude Opus 5 leads for AI agents with agentic index 55.3, at $25.00 per 1M output tokens. GPT-5.6 Sol (54.0) and Claude Fable 5 (52.8) follow. Ranked by Artificial Analysis Agentic Index; models without tool-calling support are excluded.
How is this ranking produced?
Ranked by Artificial Analysis Agentic Index; models without tool-calling support are excluded. The list rebuilds from the live model catalogue on every deploy, so a model that launches or changes price appears here without an editor rewriting the page. Last rebuild: August 3, 2026.
What does the top pick cost to run?
Claude Opus 5 costs about $12.50 for a workload of 1M input + 300K output tokens, based on the cheapest of 5 provider(s).