GPT-5.2 vs Grok Code Fast 1

OpenAI · US  |  xAI · US · Updated June 2026

Quick verdict

Pick GPT-5.2 for strong all-round reasoning or reliable structured output. Pick Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50 or low-latency code generation and terminal tasks. On a tight budget at scale, Grok Code Fast 1 is the value pick.

GPT-5.2 (OpenAI) and Grok Code Fast 1 (xAI) are two of the models people most often weigh against each other in 2026. GPT-5.2 is a capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. 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. 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

SpecGPT-5.2Grok Code Fast 1
ProviderOpenAI (US) xAI (US)
ReleasedDecember 11, 2025 August 28, 2025
Context window400K (~600 pages) 256K (~384 pages)
Price (in/out)$1.75/$14 per 1M tokens $0.2/$1.5 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Strong all-round reasoning

GPT-5.2

A capable GPT-5-generation all-rounder, now succeeded by GPT-5.5 — and it carries the larger 400K context.

Reliable structured output

GPT-5.2

A capable GPT-5-generation all-rounder, now succeeded by GPT-5.5 — and it is the newer of the two.

Broad ecosystem and tooling

GPT-5.2

GPT-5.2 lists broad ecosystem and tooling among its strengths; Grok Code Fast 1 does not.

Fast, cheap agentic coding at $0.20/$1.50

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens it undercuts GPT-5.2 ($1.75/$14 per 1M tokens), and that gap compounds at volume.

Low-latency code generation and terminal tasks

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 runs cheaper at $0.2/$1.5 per 1M tokens.

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; GPT-5.2 does not.

Lowest cost at scale

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

GPT-5.2

Its 400K window is about 1.6× larger than Grok Code Fast 1's 256K, fitting roughly 600 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens it undercuts GPT-5.2, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

GPT-5.2

Larger 400K window fits more in one prompt.

Anyone whose priority is strong all-round reasoning

GPT-5.2

It is specifically built for that.

Anyone whose priority is fast, cheap agentic coding at $0.20/$1.50

Grok Code Fast 1

That is its strongest area.

GPT-5.2: where it fits

A capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. Released December 11, 2025 by OpenAI, it is built for strong all-round reasoning, reliable structured output, broad ecosystem and tooling, and professional workflows.

Its trade-offs are real: superseded by GPT-5.5, and smaller context than flagships. At $1.75 in / $14 out per million tokens, it sits in the mid price band.

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: 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.

The bottom line for this matchup

GPT-5.2 and Grok Code Fast 1 overlap enough that the right pick depends on your specific job. Grok Code Fast 1 costs less per token; GPT-5.2 holds the larger context; and each leads in its own area — GPT-5.2 for strong all-round reasoning, Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both GPT-5.2 and Grok Code Fast 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 GPT-5.2 or Grok Code Fast 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, GPT-5.2 leans toward strong all-round reasoning while Grok Code Fast 1 leans toward fast, cheap agentic coding at $0.20/$1.50, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-5.2 or Grok Code Fast 1?

Grok Code Fast 1 is cheaper — $1.75/$14 per 1M tokens vs $0.2/$1.5 per 1M tokens, roughly 8.8× apart on input.

Which has the bigger context window?

GPT-5.2 — 400K vs 256K, about 1.6× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-5.2 and Grok Code Fast 1 together?

Yes — a multi-model platform like LumiChats gives you GPT-5.2, Grok Code Fast 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, GPT-5.2 or Grok Code Fast 1?

GPT-5.2 — released December 11, 2025, about 4 months after Grok Code Fast 1.

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.