GROK 4.20
xAI's long-context variant. 2M-token window. Reasoning mode. Vision input. Native X / web / news search. $1.25/$2.50 per million tokens.
Grok 4.20 is xAI's long-context flagship and the largest production context window in the frontier set — 2,000,000 tokens, double Gemini 3 Pro's already-massive 1M window. It pairs that window with an explicit reasoning mode for harder analytical work, vision input for diagrams and screenshots, and native X / web / news search for fresh grounding. Pricing matches Grok 4.3 at $1.25 per million input tokens and $2.50 per million output, which makes it the cheapest way to feed truly enormous prompts to a frontier model. The case for Grok 4.20: whole-monorepo analysis, multi-book research synthesis, very long video transcripts, or any workload where 1M tokens isn't enough. The case against: for everyday work the smaller Grok 4.3 is identically priced but slightly snappier, and Claude Opus 4.7 still wins on code-edit quality and writing voice. Pick Grok 4.20 when context size is the binding constraint.
Grok 4.3 is the daily-driver flagship with a 1M-token window. Grok 4.20 is the long-context variant with a 2M-token window and an explicit reasoning mode. Use 4.20 when 1M tokens isn't enough or when you want the reasoning mode for hard analytical tasks.
$1.25 per million input tokens and $2.50 per million output tokens — identical to Grok 4.3 despite the larger window. Council AI bundles it inside monthly plan budgets.
In practice, recall holds well across the window for retrieval-style questions. As with any long-context model, performance on multi-hop reasoning gradually degrades past ~1M tokens, so for very complex synthesis tasks chunk-and-merge is still worth considering.
Yes, with native tool calling. The same reliability profile as Grok 4.3 — solid for most agent flows.
Slightly slower at large input sizes due to the longer-context routing. For short prompts the difference is negligible, but you'll feel it when feeding 500K+ tokens.
Grok 4.20 has a larger window (2M vs 1M) and the cheaper price. Gemini 3 Pro has stronger multimodal (audio + video) and Google Search grounding. If your workload is pure text, Grok 4.20 wins on size and cost.