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

Side-by-side specs

SpecGrok 4.3MAI-Thinking-1
ProviderxAI (US) Microsoft (US)
ReleasedApril 30, 2026 June 2, 2026
Context window1M (~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
Modalitiestext, image, video, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Video understanding from native video input

Grok 4.3

A core design strength of Grok 4.3.

Generating PDF, PPTX, and XLSX files directly

Grok 4.3

A core design strength of Grok 4.3.

Real-time questions using live X data

Grok 4.3

A core design strength of Grok 4.3.

Very strong math reasoning (AIME 2025 97%, AIME 2026 94.5%)

MAI-Thinking-1

A core design strength of MAI-Thinking-1.

Microsoft's first in-house flagship reasoner, trained without OpenAI distillation

MAI-Thinking-1

A core design strength of MAI-Thinking-1.

Efficient reasoning at low token cost for its class

MAI-Thinking-1

A core design strength of MAI-Thinking-1.

Lowest cost at scale

MAI-Thinking-1

At Not published, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Grok 4.3

Its 1M window is about 3.9× larger, 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 June 2, 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 pricing

Frequently 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 June 2, 2026, about 33 days 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.