Grok 4.20 0309 (Reasoning)
Analysis Summary
Grok 4.20 0309 (Reasoning) is xAI's reasoning-mode variant of the Grok 4.20 series, released in March 2026. Its intelligence index of 48.5 places it in the excellent tier, supported by a strong GPQA score of 0.885 and a science benchmark of 0.447. The agentic index of 68.7 and terminal benchmark score of 0.409 confirm reliable multi-step tool use and autonomous task handling.
For businesses, this model is well suited to complex reasoning workflows, autonomous coding agents, and research-intensive tasks. The coding index of 42.2 is strong, and the tau2 score of 0.965 suggests high instruction-fidelity in agentic pipelines. Long-context reasoning (lcr 0.59) is above average, making it useful for document-heavy analysis. The main limitation is the absence of vision support in the available data.
At $2 input and $6 output per million tokens, it offers strong price-performance for a model at this capability level. Teams running agentic or reasoning-heavy workloads who want a cost-efficient alternative to the top-tier flagships should consider this model seriously.
Assessed June 6, 2026
Editorial notes
Grok 4.20 0309 in reasoning mode delivers excellent intelligence and strong agentic performance from xAI, with competitive coding capability and very attractive pricing at $2/$6 per million tokens.
Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?
Performance Profile
How Grok 4.20 0309 (Reasoning) compares
Grok 4.20 0309 (Reasoning) ranks #26 of 378 AI models we track for overall intelligence, #29 of 315 for coding, #17 of 289 for agentic tasks. At $2.00 per million input tokens it is cheaper than 16% of comparable models.
Performance Indices
Source: Artificial Analysis
Benchmark Scores
Intelligence
Technical
Content
Benchmark data from Artificial Analysis and Hugging Face
How does Grok 4.20 0309 (Reasoning) stack up?
Compare side-by-side with other professional models.
Model Information
| Provider | xAI |
| Release Date | March 10, 2026 |
| Status | Active |
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $2.00 | $0.002000 |
| Output | $6.00 | $0.006000 |
Leaderboard Categories
Frequently asked questions about Grok 4.20 0309 (Reasoning)
How much does Grok 4.20 0309 (Reasoning) cost?
Grok 4.20 0309 (Reasoning) costs $2.00 per million input tokens and $6.00 per million output tokens.
Is Grok 4.20 0309 (Reasoning) good for coding?
On our coding benchmark index, Grok 4.20 0309 (Reasoning) ranks #29 of 315 models, placing it in the top quartile of the field for code generation and debugging.
Who created Grok 4.20 0309 (Reasoning)?
Grok 4.20 0309 (Reasoning) is developed by xAI and was released on March 10, 2026.
