GPT-5.1 vs Grok 4.6

OpenAI · US  |  xAI · US · Updated June 2026

Quick verdict

Pick GPT-5.1 for adaptive reasoning that scales compute to task difficulty or general-purpose reasoning, coding and tool use. Pick Grok 4.6 for frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol or ranked #2 on artificial analysis's independent gdpval agentic test, behind only claude opus 5. On a tight budget at scale, GPT-5.1 is the value pick.

GPT-5.1 (OpenAI) and Grok 4.6 (xAI) are two of the models people most often weigh against each other in 2026. GPT-5.1 is openAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line. Grok 4.6 is xAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot. 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-5.1Grok 4.6
ProviderOpenAI (US) xAI (US)
ReleasedNovember 13, 2025 August 12, 2026
Context window400K (~600 pages) 500K (~750 pages)
Price (in/out)$1.25/$10 per 1M tokens $2/$6 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Adaptive reasoning that scales compute to task difficulty

GPT-5.1

At $1.25/$10 per 1M tokens it undercuts Grok 4.6 ($2/$6 per 1M tokens), and that gap compounds at volume.

General-purpose reasoning, coding and tool use

GPT-5.1

Grok 4.6 is comparatively weak here — coding gains (DeepSWE 65.9, APEX-Agents 57.5) are xAI's own numbers, not independently reproduced

A large ~400K context for long documents and sessions

GPT-5.1

OpenAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line — and it runs cheaper at $1.25/$10 per 1M tokens.

Frontier-tier intelligence at a value price - Artificial Analysis Intelligence Index 61, tying GPT-5.6 Sol

Grok 4.6

GPT-5.1 is comparatively weak here — premium output price at $10/1M for a now-older model

Ranked #2 on Artificial Analysis's independent GDPval agentic test, behind only Claude Opus 5

Grok 4.6

XAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot — and it carries the larger 500K context.

$2/$6 per million tokens - a fraction of Claude Opus 5 or GPT-5.6 Sol

Grok 4.6

Its 500K window holds about 1.3× more than GPT-5.1's 400K in a single prompt.

Lowest cost at scale

GPT-5.1

At $1.25/$10 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Grok 4.6

Its 500K window is about 1.3× larger than GPT-5.1's 400K, fitting roughly 750 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-5.1

At $1.25/$10 per 1M tokens it undercuts Grok 4.6, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Grok 4.6

Larger 500K window fits more in one prompt.

Anyone whose priority is adaptive reasoning that scales compute to task difficulty

GPT-5.1

It is specifically built for that.

Anyone whose priority is frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol

Grok 4.6

That is its strongest area.

GPT-5.1: where it fits

OpenAI's late-2025 GPT-5.1 at $1.25/$10 — a capable general model since surpassed by the GPT-5.2–5.6 line. Released November 13, 2025 by OpenAI, it is built for adaptive reasoning that scales compute to task difficulty, general-purpose reasoning, coding and tool use, a large ~400K context for long documents and sessions, and text and image input.

Its trade-offs are real: superseded by GPT-5.2 through GPT-5.6 — kept for compatibility rather than being current, no reliably published SWE-Bench Verified figure, exact context window unconfirmed (400K vs 410K across trackers), and premium output price at $10/1M for a now-older model. At $1.25 in / $10 out per million tokens, it sits in the mid price band.

Grok 4.6: where it fits

XAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot. Released August 12, 2026 by xAI, it is built for frontier-tier intelligence at a value price - Artificial Analysis Intelligence Index 61, tying GPT-5.6 Sol, ranked #2 on Artificial Analysis's independent GDPval agentic test, behind only Claude Opus 5, $2/$6 per million tokens - a fraction of Claude Opus 5 or GPT-5.6 Sol, and 500K-token context; available same-day in Cursor and (two days later) GitHub Copilot.

Its trade-offs: coding gains (DeepSWE 65.9, APEX-Agents 57.5) are xAI's own numbers, not independently reproduced, parameter count is undisclosed, text and image input only - not a full multimodal model, and fast-moving target: xAI says Grok 4.7 is only weeks away. At $2 in / $6 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

GPT-5.1 and Grok 4.6 overlap enough that the right pick depends on your specific job. GPT-5.1 costs less per token; Grok 4.6 holds the larger context; and each leads in its own area — GPT-5.1 for adaptive reasoning that scales compute to task difficulty, Grok 4.6 for frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both GPT-5.1 and Grok 4.6 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-5.1 or Grok 4.6 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-5.1 leans toward adaptive reasoning that scales compute to task difficulty while Grok 4.6 leans toward frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-5.1 or Grok 4.6?

GPT-5.1 is cheaper — $1.25/$10 per 1M tokens vs $2/$6 per 1M tokens, roughly 1.6× apart on input.

Which has the bigger context window?

Grok 4.6 — 500K vs 400K, about 1.3× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-5.1 and Grok 4.6 together?

Yes — a multi-model platform like LumiChats gives you GPT-5.1, Grok 4.6 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-5.1 or Grok 4.6?

Grok 4.6 — released August 12, 2026, about 9 months after GPT-5.1.

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.