Grok 4.20
xAI · released Mar 31, 2026
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...
Specification
- Context window
- 2M
- Max output
- —
- Knowledge cutoff
- Sep 1, 2025
- Parameters
- Undisclosed
- Licence
- Proprietary
- Serving providers
- 1
- Moderated
- No
- Uptime
- 100.0%
Intelligence
38.0
86th percentile
Coding
—
Coding Index
Agentic
—
Agentic Index
Output speed
93 t/s
Median across providers
Latency
427ms
Time to first token
Cost per task
$0.26
Estimated
Benchmarks
Where the score comes from
The Intelligence Index is a composite. These are the underlying evaluations this model was actually measured on.
Evaluation scores
Percentage correct · higher is better
- τ²-bench (Telecom)93.0%
- GPQA Diamond91.1%
- IFBench81.2%
- AA-LCR (long context)62.3%
- SciCode45.6%
- Terminal-Bench Hard37.9%
- Humanity's Last Exam34.5%
An evaluation missing from this list was not run for this model — it is not a zero.
View as table
| Evaluation | Score |
|---|---|
| τ²-bench (Telecom) | 93.0% |
| GPQA Diamond | 91.1% |
| IFBench | 81.2% |
| AA-LCR (long context) | 62.3% |
| SciCode | 45.6% |
| Terminal-Bench Hard | 37.9% |
| Humanity's Last Exam | 34.5% |
Against its peers
Intelligence Index · this model highlighted, nearest peers in grey
- Claude Opus 4.6Anthropic38.8
- Grok 4.20xAI38.0
- MiMo-V2.5Xiaomi38.0
- Grok 4.3xAI37.9
- Ling-3.0-flashInclusionAI37.8
- Qwen3.6 27BQwen37.7
- GPT-5.1OpenAI37.5
- Gemini 3.5 Flash LiteGoogle37.4
Peers are the models sitting closest on the Intelligence Index — the set you would realistically choose between.
View as table
| Model | Intelligence |
|---|---|
| Claude Opus 4.6 | 38.8 |
| Grok 4.20 | 38.0 |
| MiMo-V2.5 | 38.0 |
| Grok 4.3 | 37.9 |
| Ling-3.0-flash | 37.8 |
| Qwen3.6 27B | 37.7 |
| GPT-5.1 | 37.5 |
| Gemini 3.5 Flash Lite | 37.4 |
Percentile among all indexed models
Pricing
What it costs to run
List prices per million tokens, plus what one representative task works out to.
List price
- Input / 1M tokens
- $1.25
- Output / 1M tokens
- $2.5
- Cached input / 1M
- $0.2
- Blended 3:1
- $1.56
One task, estimated
$0.26
- Input tokens
- 50,000
- Output tokens
- 80,000
- Profile
- Reasoning
Estimated from list pricing: 50K input tokens plus 80K output tokens for reasoning models (25K for non-reasoning).
Serving providers
Speed and latency figures are medians across these providers, so a widely-served model reports a blend rather than any single endpoint.