Migrating from grok-4-fast-reasoning to grok-4.3
What changes when you move from grok-4-fast-reasoning to grok-4.3: prices, limits, features and parameters, read from each company's own pages.
- Status
- Retired
- Shutdown
- May 15, 2026
- Time left
- —
- To
- grok-4.3
- Status
- Active
- Shutdown
- none announced
- Time left
- —
Prices
USD per 1M tokens, standard tier| Type | grok-4-fast-reasoning | grok-4.3 | Change |
|---|---|---|---|
| Input | Not published | $1.25first seen October 5, 2026 · source | — |
| Cached input | Not published | $0.20first seen October 5, 2026 · source | — |
| Output | Not published | $2.50first seen October 5, 2026 · source | — |
Other tiers, prompt-size bands and modalities are on each model's page.
Limits
TokensNeither company publishes a context window or output limit for these models.
Benchmarks
Same benchmark, source and setting on both sides| Benchmark | grok-4-fast-reasoning | grok-4.3 | Change |
|---|---|---|---|
| Arena TextArena. Ranges don't overlap. | 1405 ±5 | 1442 ±4 | +37 |
| Arena Text: CodingArena. Ranges don't overlap. | 1439 ±9 | 1488 ±6 | +49 |
| Arena WebDevArena. Ranges don't overlap. | 1159 ±27 | 1357 ±6 | +198 |
| Arena SearchArena. Ranges don't overlap. | 1161 ±5 | 1193 ±5 | +32 |
A score from one source is never compared with another source's, and company-reported scores are compared only within the same company; settings named where they differ. Data: Arena (arena.ai), CC BY 4.0.
Features and parameters
Compare modelsNeither company publishes feature facts for these models.
Aliases
All aliasesNo aliases point at either model.
On cloud platforms
All platform dates| Model | Platform | Platform ID | Shutdown | Time left |
|---|---|---|---|---|
| grok-4-fast-reasoning | Microsoft Foundryversion 1 | grok-4-fast-reasoning | May 1, 2026Retired on May 1, 2026 | |
| grok-4.3 | Amazon Bedrock | xai.grok-4.3 | not before Jun 15, 2027Active |
Read daily from each platform's own pages. The status above uses each company's own date. Time left counts to 00:00 UTC on the shutdown date, which is the evening before in ET.
Checklist
- Change the model string from
grok-4-fast-reasoningtogrok-4.3.
Compared from AIWire's published data when this page loaded. Each fact links to the page it came from. Model pages: grok-4-fast-reasoning, grok-4.3.