Grok 4.3 vs MAI-Thinking-1
xAI · US | Microsoft · US · Updated June 2026
Quick verdict
Pick Grok 4.3 for video understanding from native video input or generating pdf, pptx, and xlsx files directly. Pick MAI-Thinking-1 for very strong math reasoning (aime 2025 97%, aime 2026 94.5%) or microsoft's first in-house flagship reasoner, trained without openai distillation. On a tight budget at scale, MAI-Thinking-1 is the value pick.
Grok 4.3 (xAI) and MAI-Thinking-1 (Microsoft) are two of the models people most often weigh against each other in 2026. Grok 4.3 is the current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5. MAI-Thinking-1 is microsoft's first fully in-house flagship reasoning model — a Claude-class reasoner built independently to cut its OpenAI dependence. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences at a glance
- ▸Context window: Grok 4.3 holds 3.9× more — 1M (~1,500 pages) vs 256K (~384 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
- ▸Recency: MAI-Thinking-1 is the newer model by about 3 months (released August 12, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
| Spec | Grok 4.3 | MAI-Thinking-1 |
|---|---|---|
| Provider | xAI (US) | Microsoft (US) |
| Released | April 30, 2026 | August 12, 2026 |
| Context window | 1M (~1,500 pages) | 256K (~384 pages) |
| Price (in/out) | $1.25/$2.5 per 1M tokens | Not published |
| Open weight? | No — API only | No — API only |
| Modalities | text, image, video, code | text, code |
| SWE-Bench Verified | Not published | Not published |
| MRCR v2 @ 1M | Not published | Not published |
Who wins what
Video understanding from native video input
Grok 4.3
The current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5 — and it carries the larger 1M context.
Generating PDF, PPTX, and XLSX files directly
Grok 4.3
Grok 4.3 lists generating PDF, PPTX, and XLSX files directly among its strengths; MAI-Thinking-1 does not.
Real-time questions using live X data
Grok 4.3
Grok 4.3 lists real-time questions using live X data among its strengths; MAI-Thinking-1 does not.
Very strong math reasoning (AIME 2025 97%, AIME 2026 94.5%)
MAI-Thinking-1
Microsoft's first fully in-house flagship reasoning model — a Claude-class reasoner built independently to cut its OpenAI dependence — and it is the newer of the two.
Microsoft's first in-house flagship reasoner, trained without OpenAI distillation
MAI-Thinking-1
Grok 4.3 is comparatively weak here — less independent benchmark coverage than OpenAI, Anthropic, or Google
Efficient reasoning at low token cost for its class
MAI-Thinking-1
Grok 4.3 is comparatively weak here — higher context pricing on requests above 200K tokens
Lowest cost at scale
MAI-Thinking-1
Its weights are open, so at volume you pay for your own hardware instead of Grok 4.3's $1.25/$2.5 per 1M tokens.
Largest single-prompt input
Grok 4.3
Its 1M window is about 3.9× larger than MAI-Thinking-1's 256K, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ MAI-Thinking-1
At Not published it undercuts Grok 4.3, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Grok 4.3
Larger 1M window fits more in one prompt.
Anyone whose priority is video understanding from native video input
→ Grok 4.3
It is specifically built for that.
Anyone whose priority is very strong math reasoning (aime 2025 97%, aime 2026 94.5%)
→ MAI-Thinking-1
That is its strongest area.
Grok 4.3: where it fits
The current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5. Released April 30, 2026 by xAI, it is built for video understanding from native video input, generating PDF, PPTX, and XLSX files directly, real-time questions using live X data, and long-context, multi-agent reasoning.
Its trade-offs are real: higher context pricing on requests above 200K tokens, and less independent benchmark coverage than OpenAI, Anthropic, or Google. At $1.25 in / $2.5 out per million tokens, it sits in the mid price band.
MAI-Thinking-1: where it fits
Microsoft's first fully in-house flagship reasoning model — a Claude-class reasoner built independently to cut its OpenAI dependence. Released August 12, 2026 by Microsoft, it is built for very strong math reasoning (AIME 2025 97%, AIME 2026 94.5%), microsoft's first in-house flagship reasoner, trained without OpenAI distillation, efficient reasoning at low token cost for its class, and competitive with Claude Opus 4.6 on SWE-Bench Pro (vendor-reported).
Its trade-offs: closed and in private preview — no open weights, no published pricing, thin availability, and benchmarks are largely self-reported.
The bottom line for this matchup
Grok 4.3 and MAI-Thinking-1 overlap enough that the right pick depends on your specific job. MAI-Thinking-1 costs less per token; Grok 4.3 holds the larger context; and each leads in its own area — Grok 4.3 for video understanding from native video input, MAI-Thinking-1 for very strong math reasoning (aime 2025 97%, aime 2026 94.5%). Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Grok 4.3 and MAI-Thinking-1 without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.
See pricingFrequently asked questions
Is Grok 4.3 or MAI-Thinking-1 better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Grok 4.3 leans toward video understanding from native video input while MAI-Thinking-1 leans toward very strong math reasoning (aime 2025 97%, aime 2026 94.5%), and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Grok 4.3 or MAI-Thinking-1?
MAI-Thinking-1 is cheaper — $1.25/$2.5 per 1M tokens vs Not published.
Which has the bigger context window?
Grok 4.3 — 1M vs 256K, about 3.9× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Grok 4.3 and MAI-Thinking-1 together?
Yes — a multi-model platform like LumiChats gives you Grok 4.3, MAI-Thinking-1 and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Grok 4.3 or MAI-Thinking-1?
MAI-Thinking-1 — released August 12, 2026, about 3 months after Grok 4.3.
Related comparisons
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.