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
- ▸Price: GPT-5.1 is about 1.6× cheaper on input ($1.25/$10 per 1M tokens vs $2/$6 per 1M tokens) — modest, but it adds up at steady volume.
- ▸Context window: Grok 4.6 holds 1.3× more — 500K (~750 pages) vs 400K (~600 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
- ▸Recency: Grok 4.6 is the newer model by about 9 months (released August 12, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
| Spec | GPT-5.1 | Grok 4.6 |
|---|---|---|
| Provider | OpenAI (US) | xAI (US) |
| Released | November 13, 2025 | August 12, 2026 |
| Context window | 400K (~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 |
| Modalities | text, image, code | text, image, code |
| SWE-Bench Verified | Not published | Not published |
| MRCR v2 @ 1M | Not 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 pricingFrequently 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.