Grok 4.20 — API Pricing & Benchmarks
Grok 4.20 is xAI's previous-generation reasoning model, released in 2026-03. The API costs $1.25 per 1M input tokens and $2.50 per 1M output tokens ($1.56 blended at a 3:1 ratio), with cached input at $0.20. It supports a 1M-token context window.
Explore provider routes and additional benchmark sources for Grok 4.20
| Provider | xAI |
| Input price / 1M tokens | $1.25 |
| Output price / 1M tokens | $2.50 |
| Cached input / 1M tokens | $0.20 |
| Blended price (3:1) | $1.56 |
| Context window | 1M |
| Max output tokens | — |
| Knowledge cutoff | 2025-09 |
| License | proprietary |
| Input modalities | T+I |
| Output speed (tok/s) | — |
| Released | 2026-03 |
| LMArena Elo | 1451 |
| SWE-bench Verified | 76.7%* |
Where Grok 4.20 fits
On a blended 3:1 basis Grok 4.20 costs $1.56 per 1M tokens, cheaper than 53% of the 80 priced models in this index. It is a previous-generation model: usually only worth choosing if you have an existing integration, negotiated pricing, or need its specific behavior, since newer siblings offer better price-performance. Cached input is priced at $0.20 (84% below standard input), which rewards prompt structures with long stable prefixes — see our caching guide.
Price history
| Period | Input $/1M | Output $/1M | Cached $/1M |
|---|---|---|---|
| 2026-07-18 → current | $1.25 | $2.50 | $0.20 |
No list-price changes recorded since tracking began. Full dataset: price-history.json (CC BY 4.0).
Alternatives at a similar price
- Grok 4.3 (xAI) — $1.56/1M blended, AA Index 37.9
- GLM-5 (Zhipu AI (Z.ai)) — $1.55/1M blended, AA Index 40.6
- Gemini 3.8 Flash (Google) — $1.50/1M blended, AA Index 58.7
- Gemini 3.7 Flash (Google) — $1.50/1M blended, AA Index 56
About xAI
xAI's Grok models compete aggressively on price: Grok 4.6 ties the proprietary frontier on the Artificial Analysis index at a mid-tier price point, and the older Grok 4.x models are among the cheapest ways to buy a large context window.