Head-to-head · 2026
Grok 4.6 vs Grok 4.3
Verdict. Grok 4.6 was the xAI flagship for long agent loops from 12 August 2026 until Grok 4.7 replaced it on 21 September 2026. Keep 4.3 when the $1.25/$2.50 band still fits. Do not treat published AA/vendor tables as SIS Model Arena winners.
AI Architect Recommendation
Two Grok seats: 4.6 for agent loops, 4.3 for cheap volume. Do not collapse them. Do not invent a SIS winner.
AI CoE pillar: Technology · model routing + Strategy · evidence honesty
- Long-running coding agents: Grok 4.6
- Bulk fan-out workers: Grok 4.3
- SIS Model Arena contestants: Stay on Claude receipts until a Grok 4.6 JSON run exists
| Grok 4.6 | Grok 4.3 | |
|---|---|---|
| Provider | xAI | xAI |
| Released | 2026-08-12 | 2026-04-30 |
| Context | 500K | 1M |
| Max output | — | — |
| Input /1M | $2.00 | $1.25 |
| Output /1M | $6.00 | $2.50 |
| Modalities | text, vision | text, vision, video |
The analysis
Grok 4.6 shipped 12 August 2026 as a same-scale post-training refresh of Grok 4.5. Official High scores put it at 61 on the Artificial Analysis Intelligence Index. Grok 4.3 remains the earlier cheap-frontier SKU at $1.25/$2.50 with a 1M context window.
The routing fork is price versus published agent scores. 4.6 stays $2/$6 under 200k prompt tokens and doubles above that. 4.3 is still cheaper per token. 4.6 was the model xAI pointed at long-running agents in August 2026; 4.3 is not retired from the cheap tier.
The Starlight Model Arena has receipts for Claude-native cards, not for Grok 4.6. This page is a catalog comparison, not a battle result.
Pick Grok 4.6 if…
- New xAI API work that needed the flagship as of August 2026
- Long-running coding or knowledge-work loops that can stay under 200k tokens
- Cases where 4.5 stamina failed and you want the documented 4.6 refresh
Pick Grok 4.3 if…
- High-volume, error-tolerant jobs that must stay at $1.25/$2.50
- Workloads that actually need the older 1M context window
- Anything you already measured on 4.3 and have no reason to move
Grok 4.6
xAI flagship from 12 August to 21 September 2026: same-scale agent refresh of 4.5, AA Index 61, $2/$6 under 200k. No Starlight arena receipt yet.
Grok 4.3
Previous cheap-frontier Grok — superseded as flagship by Grok 4.6 on 12 August 2026.