Pick GPT-5.1 for adaptive reasoning that scales compute to task difficulty or general-purpose reasoning, coding and tool use. Pick Kimi K2.7 Code for long-horizon agentic software engineering or token-efficient reasoning (~30% fewer than k2.6). Choose Kimi K2.7 Code if you need self-hosting or data privacy; GPT-5.1 if you want a managed API.
GPT-5.1 (OpenAI, US) and Kimi K2.7 Code (Moonshot AI, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. 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. Kimi K2.7 Code is moonshot AI's open-weight 1T-parameter MoE model (32B active) tuned for long-horizon agentic coding, always reasoning yet ~30% more token-efficient than K2.6. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.
Key differences
Price: Kimi K2.7 Code is about 1.3× cheaper on input ($0.95/$4 per 1M tokens vs $1.25/$10 per 1M tokens) — modest, but it adds up at steady volume.
Context window: GPT-5.1 holds 1.5× more — 400K (~600 pages) vs 256K (~393 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Recency: Kimi K2.7 Code is the newer model by about 7 months (released June 12, 2026), usually meaning fresher training data and capabilities.
Ecosystem: this is a US-vs-China matchup — they differ in pricing philosophy, data-residency options, and tooling ecosystems, not only benchmarks.
Specifications
Spec
GPT-5.1
Kimi K2.7 Code
Provider
OpenAI (US)
Moonshot AI (China)
Released
November 13, 2025
June 12, 2026
Context window
400K (~600 pages)
256K (~393 pages)
Price (in/out)
$1.25/$10 per 1M tokens
$0.95/$4 per 1M tokens
Open weight?
No — API only
Yes — self-hostable
Modalities
text, image, code
text, image, video, 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 — 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 carries the larger 400K context.
General-purpose reasoning, coding and tool use: GPT-5.1 — GPT-5.1 lists general-purpose reasoning, coding and tool use among its strengths; Kimi K2.7 Code does not.
A large ~400K context for long documents and sessions: GPT-5.1 — Its 400K window holds about 1.5× more than Kimi K2.7 Code's 256K in a single prompt.
Long-horizon agentic software engineering: Kimi K2.7 Code — Moonshot AI's open-weight 1T-parameter MoE model (32B active) tuned for long-horizon agentic coding, always reasoning yet ~30% more token-efficient than K2.6 — and it runs cheaper at $0.95/$4 per 1M tokens.
Token-efficient reasoning (~30% fewer than K2.6): Kimi K2.7 Code — Moonshot AI's open-weight 1T-parameter MoE model (32B active) tuned for long-horizon agentic coding, always reasoning yet ~30% more token-efficient than K2.6 — and its weights are open while GPT-5.1 is API-only.
Open-weight 1T MoE, self-hostable: Kimi K2.7 Code — Open weights make this possible at all — GPT-5.1 is API-only, so it cannot leave the vendor's servers.
Lowest cost at scale: Kimi K2.7 Code — At $0.95/$4 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input: GPT-5.1 — Its 400K window is about 1.5× larger than Kimi K2.7 Code's 256K, fitting roughly 600 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume: Kimi K2.7 Code — At $0.95/$4 per 1M tokens it undercuts GPT-5.1, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: GPT-5.1 — Larger 400K window fits more in one prompt.
A team with data-privacy or self-hosting needs: Kimi K2.7 Code — Open weights let you run it on your own hardware; GPT-5.1 is API-only.
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 long-horizon agentic software engineering: Kimi K2.7 Code — That is its strongest area.
An enterprise with regional data-residency rules: GPT-5.1 or Kimi K2.7 Code — Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.
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.
Kimi K2.7 Code: where it fits
Moonshot AI's open-weight 1T-parameter MoE model (32B active) tuned for long-horizon agentic coding, always reasoning yet ~30% more token-efficient than K2.6. Released June 12, 2026 by Moonshot AI, it is built for long-horizon agentic software engineering, token-efficient reasoning (~30% fewer than K2.6), open-weight 1T MoE, self-hostable, and multi-turn tool use with preserved reasoning.
Its trade-offs: only self-reported benchmarks; no SWE-Bench Verified, and thinking mode and sampling params can't be disabled. At $0.95 in / $4 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
The defining split here is open vs. closed. Kimi K2.7 Code gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-5.1 gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.
Frequently asked questions
Is GPT-5.1 or Kimi K2.7 Code 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 Kimi K2.7 Code leans toward long-horizon agentic software engineering, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.1 or Kimi K2.7 Code?
Kimi K2.7 Code is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-5.1 is API-metered at $1.25/$10 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.
Which has the bigger context window?
GPT-5.1 — 400K vs 256K, about 1.5× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-5.1 and Kimi K2.7 Code together?
Yes — a multi-model platform like LumiChats gives you GPT-5.1, Kimi K2.7 Code 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 Kimi K2.7 Code?
Kimi K2.7 Code — released June 12, 2026, about 7 months after GPT-5.1.
GPT-5.1 vs Kimi K2.7 Code
OpenAI · US | Moonshot AI · China · 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 Kimi K2.7 Code for long-horizon agentic software engineering or token-efficient reasoning (~30% fewer than k2.6). Choose Kimi K2.7 Code if you need self-hosting or data privacy; GPT-5.1 if you want a managed API.
GPT-5.1 (OpenAI, US) and Kimi K2.7 Code (Moonshot AI, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. 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. Kimi K2.7 Code is moonshot AI's open-weight 1T-parameter MoE model (32B active) tuned for long-horizon agentic coding, always reasoning yet ~30% more token-efficient than K2.6. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.
Key differences at a glance
▸Price: Kimi K2.7 Code is about 1.3× cheaper on input ($0.95/$4 per 1M tokens vs $1.25/$10 per 1M tokens) — modest, but it adds up at steady volume.
▸Context window: GPT-5.1 holds 1.5× more — 400K (~600 pages) vs 256K (~393 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
▸Recency: Kimi K2.7 Code is the newer model by about 7 months (released June 12, 2026), usually meaning fresher training data and capabilities.
▸Ecosystem: this is a US-vs-China matchup — they differ in pricing philosophy, data-residency options, and tooling ecosystems, not only benchmarks.
Side-by-side specs
Spec
GPT-5.1
Kimi K2.7 Code
Provider
OpenAI (US)
Moonshot AI (China)
Released
November 13, 2025
June 12, 2026
Context window
400K (~600 pages)
256K (~393 pages)
Price (in/out)
$1.25/$10 per 1M tokens
$0.95/$4 per 1M tokens
Open weight?
No — API only
Yes — self-hostable
Modalities
text, image, code
text, image, video, 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
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 carries the larger 400K context.
General-purpose reasoning, coding and tool use
GPT-5.1
GPT-5.1 lists general-purpose reasoning, coding and tool use among its strengths; Kimi K2.7 Code does not.
A large ~400K context for long documents and sessions
GPT-5.1
Its 400K window holds about 1.5× more than Kimi K2.7 Code's 256K in a single prompt.
Long-horizon agentic software engineering
Kimi K2.7 Code
Moonshot AI's open-weight 1T-parameter MoE model (32B active) tuned for long-horizon agentic coding, always reasoning yet ~30% more token-efficient than K2.6 — and it runs cheaper at $0.95/$4 per 1M tokens.
Token-efficient reasoning (~30% fewer than K2.6)
Kimi K2.7 Code
Moonshot AI's open-weight 1T-parameter MoE model (32B active) tuned for long-horizon agentic coding, always reasoning yet ~30% more token-efficient than K2.6 — and its weights are open while GPT-5.1 is API-only.
Open-weight 1T MoE, self-hostable
Kimi K2.7 Code
Open weights make this possible at all — GPT-5.1 is API-only, so it cannot leave the vendor's servers.
Lowest cost at scale
Kimi K2.7 Code
At $0.95/$4 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input
GPT-5.1
Its 400K window is about 1.5× larger than Kimi K2.7 Code's 256K, fitting roughly 600 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Kimi K2.7 Code
At $0.95/$4 per 1M tokens it undercuts GPT-5.1, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ GPT-5.1
Larger 400K window fits more in one prompt.
A team with data-privacy or self-hosting needs
→ Kimi K2.7 Code
Open weights let you run it on your own hardware; GPT-5.1 is API-only.
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 long-horizon agentic software engineering
→ Kimi K2.7 Code
That is its strongest area.
An enterprise with regional data-residency rules
→ GPT-5.1 or Kimi K2.7 Code
Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.
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.
Kimi K2.7 Code: where it fits
Moonshot AI's open-weight 1T-parameter MoE model (32B active) tuned for long-horizon agentic coding, always reasoning yet ~30% more token-efficient than K2.6. Released June 12, 2026 by Moonshot AI, it is built for long-horizon agentic software engineering, token-efficient reasoning (~30% fewer than K2.6), open-weight 1T MoE, self-hostable, and multi-turn tool use with preserved reasoning.
Its trade-offs: only self-reported benchmarks; no SWE-Bench Verified, and thinking mode and sampling params can't be disabled. At $0.95 in / $4 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
The defining split here is open vs. closed. Kimi K2.7 Code gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-5.1 gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.
Want both GPT-5.1 and Kimi K2.7 Code 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 Kimi K2.7 Code leans toward long-horizon agentic software engineering, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.1 or Kimi K2.7 Code?
Kimi K2.7 Code is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-5.1 is API-metered at $1.25/$10 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.
Which has the bigger context window?
GPT-5.1 — 400K vs 256K, about 1.5× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-5.1 and Kimi K2.7 Code together?
Yes — a multi-model platform like LumiChats gives you GPT-5.1, Kimi K2.7 Code 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 Kimi K2.7 Code?
Kimi K2.7 Code — released June 12, 2026, about 7 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.