Pick GPT-5.1 for adaptive reasoning that scales compute to task difficulty or general-purpose reasoning, coding and tool use. Pick Grok 4.7 for 2.1 trillion parameters, up 40% from grok 4.6's 1.5 trillion, at the same $2/$6 per million token price or deepswe v1.1 (high effort): 71.0%, up from grok 4.6's 65.2%; cursorbench 4.0: 46.3%, up from 40.4%. On a tight budget at scale, GPT-5.1 is the value pick.
GPT-5.1 (OpenAI) and Grok 4.7 (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 4.7 is xAI's September 21, 2026 update — a 2.1T-parameter model trained partly on SpaceX hardware data, same price as Grok 4.6 but stronger on coding benchmarks. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences
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 4.7 holds 1.3× more — 500K tokens (~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 4.7 is the newer model by about 10 months (released September 21, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
GPT-5.1
Grok 4.7
Provider
OpenAI (US)
xAI (US)
Released
November 13, 2025
September 21, 2026
Context window
400K (~600 pages)
500K tokens (~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 4.7 ($2/$6 per 1M tokens), and that gap compounds at volume.
General-purpose reasoning, coding and tool use: 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.
A large ~400K context for long documents and sessions: GPT-5.1 — Grok 4.7 is comparatively weak here — 500K context window trails several rivals now sitting at 1M+
2.1 trillion parameters, up 40% from Grok 4.6's 1.5 trillion, at the same $2/$6 per million token price: Grok 4.7 — Its 500K tokens window holds about 1.3× more than GPT-5.1's 400K in a single prompt.
DeepSWE v1.1 (high effort): 71.0%, up from Grok 4.6's 65.2%; CursorBench 4.0: 46.3%, up from 40.4%: Grok 4.7 — XAI's September 21, 2026 update — a 2.1T-parameter model trained partly on SpaceX hardware data, same price as Grok 4.6 but stronger on coding benchmarks — and it carries the larger 500K tokens context.
Trained with supplemental SpaceX data (Starlink telemetry, manufacturing records, engineering failure logs) — xAI says this improves reasoning about hardware and physical systems: Grok 4.7 — XAI's September 21, 2026 update — a 2.1T-parameter model trained partly on SpaceX hardware data, same price as Grok 4.6 but stronger on coding benchmarks — and it is the newer of the two.
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 4.7 — Its 500K tokens 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 4.7, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: Grok 4.7 — Larger 500K tokens 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 2.1 trillion parameters, up 40% from grok 4.6's 1.5 trillion, at the same $2/$6 per million token price: Grok 4.7 — 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 4.7: where it fits
XAI's September 21, 2026 update — a 2.1T-parameter model trained partly on SpaceX hardware data, same price as Grok 4.6 but stronger on coding benchmarks. Released September 21, 2026 by xAI, it is built for 2.1 trillion parameters, up 40% from Grok 4.6's 1.5 trillion, at the same $2/$6 per million token price, deepSWE v1.1 (high effort): 71.0%, up from Grok 4.6's 65.2%; CursorBench 4.0: 46.3%, up from 40.4%, trained with supplemental SpaceX data (Starlink telemetry, manufacturing records, engineering failure logs) — xAI says this improves reasoning about hardware and physical systems, and xAI's strongest safety guardrails to date, per the company.
Its trade-offs: release was delayed at least five times since late July 2026 before shipping, 500K context window trails several rivals now sitting at 1M+, and reviewers note it arrives "late to the AI frontier party" against GPT-6 Astra, Claude Fable 5.1 and Opus 5.5, all shipped in the weeks just before it. 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 4.7 overlap enough that the right pick depends on your specific job. GPT-5.1 costs less per token; Grok 4.7 holds the larger context; and each leads in its own area — GPT-5.1 for adaptive reasoning that scales compute to task difficulty, Grok 4.7 for 2.1 trillion parameters, up 40% from grok 4.6's 1.5 trillion, at the same $2/$6 per million token price. Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is GPT-5.1 or Grok 4.7 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 4.7 leans toward 2.1 trillion parameters, up 40% from grok 4.6's 1.5 trillion, at the same $2/$6 per million token price, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.1 or Grok 4.7?
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 4.7 — 500K tokens 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 4.7 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.1, Grok 4.7 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 4.7?
Grok 4.7 — released September 21, 2026, about 10 months after GPT-5.1.
GPT-5.1 vs Grok 4.7
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 4.7 for 2.1 trillion parameters, up 40% from grok 4.6's 1.5 trillion, at the same $2/$6 per million token price or deepswe v1.1 (high effort): 71.0%, up from grok 4.6's 65.2%; cursorbench 4.0: 46.3%, up from 40.4%. On a tight budget at scale, GPT-5.1 is the value pick.
GPT-5.1 (OpenAI) and Grok 4.7 (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 4.7 is xAI's September 21, 2026 update — a 2.1T-parameter model trained partly on SpaceX hardware data, same price as Grok 4.6 but stronger on coding benchmarks. 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 4.7 holds 1.3× more — 500K tokens (~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 4.7 is the newer model by about 10 months (released September 21, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
GPT-5.1
Grok 4.7
Provider
OpenAI (US)
xAI (US)
Released
November 13, 2025
September 21, 2026
Context window
400K (~600 pages)
500K tokens (~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 4.7 ($2/$6 per 1M tokens), and that gap compounds at volume.
General-purpose reasoning, coding and tool use
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.
A large ~400K context for long documents and sessions
GPT-5.1
Grok 4.7 is comparatively weak here — 500K context window trails several rivals now sitting at 1M+
2.1 trillion parameters, up 40% from Grok 4.6's 1.5 trillion, at the same $2/$6 per million token price
Grok 4.7
Its 500K tokens window holds about 1.3× more than GPT-5.1's 400K in a single prompt.
DeepSWE v1.1 (high effort): 71.0%, up from Grok 4.6's 65.2%; CursorBench 4.0: 46.3%, up from 40.4%
Grok 4.7
XAI's September 21, 2026 update — a 2.1T-parameter model trained partly on SpaceX hardware data, same price as Grok 4.6 but stronger on coding benchmarks — and it carries the larger 500K tokens context.
Trained with supplemental SpaceX data (Starlink telemetry, manufacturing records, engineering failure logs) — xAI says this improves reasoning about hardware and physical systems
Grok 4.7
XAI's September 21, 2026 update — a 2.1T-parameter model trained partly on SpaceX hardware data, same price as Grok 4.6 but stronger on coding benchmarks — and it is the newer of the two.
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 4.7
Its 500K tokens 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 4.7, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Grok 4.7
Larger 500K tokens 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 2.1 trillion parameters, up 40% from grok 4.6's 1.5 trillion, at the same $2/$6 per million token price
→ Grok 4.7
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 4.7: where it fits
XAI's September 21, 2026 update — a 2.1T-parameter model trained partly on SpaceX hardware data, same price as Grok 4.6 but stronger on coding benchmarks. Released September 21, 2026 by xAI, it is built for 2.1 trillion parameters, up 40% from Grok 4.6's 1.5 trillion, at the same $2/$6 per million token price, deepSWE v1.1 (high effort): 71.0%, up from Grok 4.6's 65.2%; CursorBench 4.0: 46.3%, up from 40.4%, trained with supplemental SpaceX data (Starlink telemetry, manufacturing records, engineering failure logs) — xAI says this improves reasoning about hardware and physical systems, and xAI's strongest safety guardrails to date, per the company.
Its trade-offs: release was delayed at least five times since late July 2026 before shipping, 500K context window trails several rivals now sitting at 1M+, and reviewers note it arrives "late to the AI frontier party" against GPT-6 Astra, Claude Fable 5.1 and Opus 5.5, all shipped in the weeks just before it. 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 4.7 overlap enough that the right pick depends on your specific job. GPT-5.1 costs less per token; Grok 4.7 holds the larger context; and each leads in its own area — GPT-5.1 for adaptive reasoning that scales compute to task difficulty, Grok 4.7 for 2.1 trillion parameters, up 40% from grok 4.6's 1.5 trillion, at the same $2/$6 per million token price. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both GPT-5.1 and Grok 4.7 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.
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 4.7 leans toward 2.1 trillion parameters, up 40% from grok 4.6's 1.5 trillion, at the same $2/$6 per million token price, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.1 or Grok 4.7?
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 4.7 — 500K tokens 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 4.7 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.1, Grok 4.7 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 4.7?
Grok 4.7 — released September 21, 2026, about 10 months after GPT-5.1.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.