Pick Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50 or low-latency code generation and terminal tasks. Pick MAI-1-preview for microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on openai or ranked in the top 15 on lm arena at launch. On a tight budget at scale, MAI-1-preview is the value pick.
Grok Code Fast 1 (xAI) and MAI-1-preview (Microsoft) are two of the models people most often weigh against each other in 2026. Grok Code Fast 1 is xAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. MAI-1-preview is microsoft's first fully in-house foundation model - a strategic break from sole reliance on OpenAI, trained on ~15,000 H100 GPUs. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences
Context window: Grok Code Fast 1 holds 2× more — 256K (~384 pages) vs 128K (~192 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Specifications
Spec
Grok Code Fast 1
MAI-1-preview
Provider
xAI (US)
Microsoft (US)
Released
August 28, 2025
August 28, 2025
Context window
256K (~384 pages)
128K (~192 pages)
Price (in/out)
$0.2/$1.5 per 1M tokens
Not published
Open weight?
No — API only
No — API only
Modalities
text, code
text, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Fast, cheap agentic coding at $0.20/$1.50: Grok Code Fast 1 — XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality — and it carries the larger 256K context.
Low-latency code generation and terminal tasks: Grok Code Fast 1 — Grok Code Fast 1 lists low-latency code generation and terminal tasks among its strengths; MAI-1-preview does not.
High-volume coding pipelines where speed beats peak quality: Grok Code Fast 1 — Grok Code Fast 1 lists high-volume coding pipelines where speed beats peak quality among its strengths; MAI-1-preview does not.
Microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on OpenAI: MAI-1-preview — Grok Code Fast 1 is comparatively weak here — a speed-tier coding model, not a frontier reasoner
Ranked in the top 15 on LM Arena at launch: MAI-1-preview — MAI-1-preview lists ranked in the top 15 on LM Arena at launch among its strengths; Grok Code Fast 1 does not.
Trained on roughly 15,000 NVIDIA H100 GPUs, a genuine internal infrastructure investment: MAI-1-preview — MAI-1-preview lists trained on roughly 15,000 NVIDIA H100 GPUs, a genuine internal infrastructure investment among its strengths; Grok Code Fast 1 does not.
Lowest cost at scale: MAI-1-preview — Its weights are open, so at volume you pay for your own hardware instead of Grok Code Fast 1's $0.2/$1.5 per 1M tokens.
Largest single-prompt input: Grok Code Fast 1 — Its 256K window is about 2× larger than MAI-1-preview's 128K, fitting roughly 384 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume: MAI-1-preview — At Not published it undercuts Grok Code Fast 1, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: Grok Code Fast 1 — Larger 256K window fits more in one prompt.
Anyone whose priority is fast, cheap agentic coding at $0.20/$1.50: Grok Code Fast 1 — It is specifically built for that.
Anyone whose priority is microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on openai: MAI-1-preview — That is its strongest area.
Grok Code Fast 1: where it fits
XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Released August 28, 2025 by xAI, it is built for fast, cheap agentic coding at $0.20/$1.50, low-latency code generation and terminal tasks, high-volume coding pipelines where speed beats peak quality, and a 256K window sized for real codebases.
Its trade-offs are real: text and code only — no image, audio or video input, xAI did not publish a SWE-Bench Verified score, a speed-tier coding model, not a frontier reasoner, and narrow focus — built for code, not general knowledge work. At $0.2 in / $1.5 out per million tokens, it sits in the budget price band.
MAI-1-preview: where it fits
Microsoft's first fully in-house foundation model - a strategic break from sole reliance on OpenAI, trained on ~15,000 H100 GPUs. Released August 28, 2025 by Microsoft, it is built for microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on OpenAI, ranked in the top 15 on LM Arena at launch, trained on roughly 15,000 NVIDIA H100 GPUs, a genuine internal infrastructure investment, and rolled into Copilot alongside OpenAI models, giving Microsoft a real second option.
Its trade-offs: a 'preview' release, not yet positioned as Microsoft's primary Copilot model, no public per-token API pricing - not sold as a standalone product, and distinct from Microsoft's later MAI-Thinking-1 reasoning model - an earlier, more general-purpose entry.
The bottom line for this matchup
Grok Code Fast 1 and MAI-1-preview overlap enough that the right pick depends on your specific job. MAI-1-preview costs less per token; Grok Code Fast 1 holds the larger context; and each leads in its own area — Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50, MAI-1-preview for microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on openai. Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is Grok Code Fast 1 or MAI-1-preview 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 Code Fast 1 leans toward fast, cheap agentic coding at $0.20/$1.50 while MAI-1-preview leans toward microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on openai, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Grok Code Fast 1 or MAI-1-preview?
MAI-1-preview is cheaper — $0.2/$1.5 per 1M tokens vs Not published.
Which has the bigger context window?
Grok Code Fast 1 — 256K vs 128K, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Grok Code Fast 1 and MAI-1-preview together?
Yes — a multi-model platform like LumiChats gives you Grok Code Fast 1, MAI-1-preview 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 Code Fast 1 or MAI-1-preview?
They were released around the same time (August 28, 2025 and August 28, 2025).
Grok Code Fast 1 vs MAI-1-preview
xAI · US | Microsoft · US · Updated June 2026
Quick verdict
Pick Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50 or low-latency code generation and terminal tasks. Pick MAI-1-preview for microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on openai or ranked in the top 15 on lm arena at launch. On a tight budget at scale, MAI-1-preview is the value pick.
Grok Code Fast 1 (xAI) and MAI-1-preview (Microsoft) are two of the models people most often weigh against each other in 2026. Grok Code Fast 1 is xAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. MAI-1-preview is microsoft's first fully in-house foundation model - a strategic break from sole reliance on OpenAI, trained on ~15,000 H100 GPUs. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences at a glance
▸Context window: Grok Code Fast 1 holds 2× more — 256K (~384 pages) vs 128K (~192 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Side-by-side specs
Spec
Grok Code Fast 1
MAI-1-preview
Provider
xAI (US)
Microsoft (US)
Released
August 28, 2025
August 28, 2025
Context window
256K (~384 pages)
128K (~192 pages)
Price (in/out)
$0.2/$1.5 per 1M tokens
Not published
Open weight?
No — API only
No — API only
Modalities
text, code
text, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Fast, cheap agentic coding at $0.20/$1.50
Grok Code Fast 1
XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality — and it carries the larger 256K context.
Low-latency code generation and terminal tasks
Grok Code Fast 1
Grok Code Fast 1 lists low-latency code generation and terminal tasks among its strengths; MAI-1-preview does not.
High-volume coding pipelines where speed beats peak quality
Grok Code Fast 1
Grok Code Fast 1 lists high-volume coding pipelines where speed beats peak quality among its strengths; MAI-1-preview does not.
Microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on OpenAI
MAI-1-preview
Grok Code Fast 1 is comparatively weak here — a speed-tier coding model, not a frontier reasoner
Ranked in the top 15 on LM Arena at launch
MAI-1-preview
MAI-1-preview lists ranked in the top 15 on LM Arena at launch among its strengths; Grok Code Fast 1 does not.
Trained on roughly 15,000 NVIDIA H100 GPUs, a genuine internal infrastructure investment
MAI-1-preview
MAI-1-preview lists trained on roughly 15,000 NVIDIA H100 GPUs, a genuine internal infrastructure investment among its strengths; Grok Code Fast 1 does not.
Lowest cost at scale
MAI-1-preview
Its weights are open, so at volume you pay for your own hardware instead of Grok Code Fast 1's $0.2/$1.5 per 1M tokens.
Largest single-prompt input
Grok Code Fast 1
Its 256K window is about 2× larger than MAI-1-preview's 128K, fitting roughly 384 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ MAI-1-preview
At Not published it undercuts Grok Code Fast 1, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Grok Code Fast 1
Larger 256K window fits more in one prompt.
Anyone whose priority is fast, cheap agentic coding at $0.20/$1.50
→ Grok Code Fast 1
It is specifically built for that.
Anyone whose priority is microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on openai
→ MAI-1-preview
That is its strongest area.
Grok Code Fast 1: where it fits
XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Released August 28, 2025 by xAI, it is built for fast, cheap agentic coding at $0.20/$1.50, low-latency code generation and terminal tasks, high-volume coding pipelines where speed beats peak quality, and a 256K window sized for real codebases.
Its trade-offs are real: text and code only — no image, audio or video input, xAI did not publish a SWE-Bench Verified score, a speed-tier coding model, not a frontier reasoner, and narrow focus — built for code, not general knowledge work. At $0.2 in / $1.5 out per million tokens, it sits in the budget price band.
MAI-1-preview: where it fits
Microsoft's first fully in-house foundation model - a strategic break from sole reliance on OpenAI, trained on ~15,000 H100 GPUs. Released August 28, 2025 by Microsoft, it is built for microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on OpenAI, ranked in the top 15 on LM Arena at launch, trained on roughly 15,000 NVIDIA H100 GPUs, a genuine internal infrastructure investment, and rolled into Copilot alongside OpenAI models, giving Microsoft a real second option.
Its trade-offs: a 'preview' release, not yet positioned as Microsoft's primary Copilot model, no public per-token API pricing - not sold as a standalone product, and distinct from Microsoft's later MAI-Thinking-1 reasoning model - an earlier, more general-purpose entry.
The bottom line for this matchup
Grok Code Fast 1 and MAI-1-preview overlap enough that the right pick depends on your specific job. MAI-1-preview costs less per token; Grok Code Fast 1 holds the larger context; and each leads in its own area — Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50, MAI-1-preview for microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on openai. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Grok Code Fast 1 and MAI-1-preview 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.
Is Grok Code Fast 1 or MAI-1-preview 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 Code Fast 1 leans toward fast, cheap agentic coding at $0.20/$1.50 while MAI-1-preview leans toward microsoft's first fully in-house, end-to-end foundation model - a historic break from relying solely on openai, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Grok Code Fast 1 or MAI-1-preview?
MAI-1-preview is cheaper — $0.2/$1.5 per 1M tokens vs Not published.
Which has the bigger context window?
Grok Code Fast 1 — 256K vs 128K, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Grok Code Fast 1 and MAI-1-preview together?
Yes — a multi-model platform like LumiChats gives you Grok Code Fast 1, MAI-1-preview 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 Code Fast 1 or MAI-1-preview?
They were released around the same time (August 28, 2025 and August 28, 2025).
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.