xAI · Released Mar 31, 2026
Grok 4.20
Grok 4.20 is a reasoning model from SpaceXAI with industry-leading speed and agentic tool calling capabilities. It combines the lowest hallucination rate on the market with strict prompt adherance, delivering...
- Top 35%Terminal-Bench
- Top 42%ARC-AGI-2
- Top 50%ARC-AGI-1
- Released
- Mar 31 2026
- Context window
- 2M 1.8M out
- Input / 1M tokens
- $1.25
- Output / 1M tokens
- $2.50
Where to run it
Providers
Cheapest: xAI at $1.25 / $2.50 per 1M input / output tokens — 50% less than the priciest option.
| Provider | Input | Output | Cache read | Context | Max output | Uptime | vs. best |
|---|---|---|---|---|---|---|---|
| xAI | $1.25 | $2.50 | $0.20 | 2M | 1.8M | 100%24h | Cheapest |
| xAIzdr | $1.25 | $2.50 | $0.20 | 2M | 1.8M | 99.7%24h | Cheapest |
| xAIzdr/priority | $2.50 | $5.00 | $0.40 | 2M | 1.8M | 100%24h | +100% |
| xAIpriority | $2.50 | $5.00 | $0.40 | 2M | 1.8M | 100%24h | +100% |
Value
Price vs. performance
Grok 4.20 Other xAI Other labs Value frontier · Terminal-Bench vs. input price per 1M tokens (log scale) · Drag to pan, pinch or Ctrl + scroll to zoom, double-click to zoom in.
Benchmarks
7 benchmark scores
| Benchmark | Score | Rank | Leader |
|---|---|---|---|
| Terminal-BenchSoftware engineering · Tasks completed with the programs in a real terminal (best agent) | 57.3% | #14of 40 | GPT-5.584.7% |
| Vending-Bench 2Agents & computer use · Run a simulated vending business for a year (final balance) | $4,663 | #32of 61 | GPT-6 Astra$15,515 |
| WebDev ArenaDesign & visual · People vote on which model builds the better website (Elo) | 1374 | #70of 88 | Claude Opus 5.51820 |
| Blueprint-Bench 2Design & visual · Turn apartment photos into 2D floor plans | 0.0% | #29of 32 | Gemini 4 Argon54.4% |
| ARC-AGI-2Reasoning & knowledge · Few-shot abstract reasoning on grid puzzles | 65.1% | #26of 63 | GPT-6 Astra95.0% |
| ARC-AGI-1Reasoning & knowledge · Pattern induction from input–output examples | 89.5% | #31of 63 | Gemini 4 Argon98.5% |
| LMCAReasoning & knowledge · Judge the quality of conceptual arguments like experts | 38.7% | #54of 96 | Claude Sonnet 5.568.3% |
Specs
Details
- Model ID
x-ai/grok-4.20- Developer
- xAI
- Release date
- Mar 31, 2026 ·
- Context window
- 2,000,000 tokens
- Max output
- 1,800,000 tokens
- API price
- $1.25 / $2.50 per 1M input / output tokens
- Providers
- 1
- Input types
- text, image, file
- Reasoning
- Yes
- Tool calling
- Yes
- Open weights
- No
- Free tier
- No
Release date, prices and providers from OpenRouter's catalog; buying directly from a provider can cost a little differently. Uptime is the share of OpenRouter requests each provider served over the last day. Benchmark scores are the best result per benchmark from Epoch AI, licensed CC BY 4.0. Rank counts every model tracked here with a score.