GPT-6 Sol vs Kimi K3 256K
GPT-6 Sol leads overall, D+ to D. GPT-6 Sol is about 13x cheaper per task. By suite, Kimi K3 256K takes real-world issues (C- to D-) and GPT-6 Sol takes spec planning (C to D+). Take Kimi K3 256K anyway when you want the side that is ahead on real-world issues.Measured
Each agent graded on the same private suites, running headless through its own tools. Advantages are oriented so a win is a win, whichever way the metric runs.
Verdict: Kimi K3 256K vs GPT-6 Sol
GPT-6 Sol leads overall, D+ to D. By suite: Kimi K3 256K takes real-world issues, C- to D- (57% vs 38% capability); GPT-6 Sol takes spec planning, C to D+ (64% vs 53% capability); GPT-6 Sol takes vibe coding, D+ to F (51% vs 24% capability). GPT-6 Sol used 5% of ChatGPT Plus's weekly limit per pass, $0.012 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1% of ChatGPT Pro 5x's weekly limit (est, about $0.012 per task). Kimi K3 256K used 34% of Kimi Allegretto's weekly limit per pass, $0.161 per task at the listed price. Per task, GPT-6 Sol is about 13x cheaper ($0.012 vs $0.161). GPT-6 Sol is faster on real-world issues: a median task takes 2m 44s against 4m 5s. Both finished every task on it. Reasons to pick Kimi K3 256K anyway: it leads on real-world issues (C- to D-).
Changed since W38: Kimi K3 256K: real-world issues usage 22% to 23% of the weekly limit, spec planning D to D+, spec planning usage 9% to 11% of the weekly limit, vibe coding D+ to C-, vibe coding usage 2.6% to 3% of the weekly limit.
| Dimension | GPT-6 Sol | Kimi K3 256K | Advantage |
|---|---|---|---|
| Capability | 38% | 57% | +18% (Kimi K3 256K leads) |
| Median task time | 2m 44s | 4m 5s | 1m 21s faster (GPT-6 Sol leads) |
| Approx. task cost | $0.012 / task | $0.138 / task | $0.125 / task lower (GPT-6 Sol leads) |
GPT-6 Sol: 4.0% of ChatGPT Plus (37.0% / 5h, 4.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. Kimi K3 256K: 115.0% of Kimi Allegretto (115.0% / 5h, 23.0% / 1w) per run. Its weekly limit holds about 5 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-6 Sol | Kimi K3 256K | Advantage |
|---|---|---|---|
| Capability | 64% | 53% | +11% (GPT-6 Sol leads) |
| Median task time | 2m 23s | 5m 36s | 3m 13s faster (GPT-6 Sol leads) |
| Approx. task cost | $0.011 / task | $0.247 / task | $0.235 / task lower (GPT-6 Sol leads) |
GPT-6 Sol: 1.0% of ChatGPT Plus (8.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. Kimi K3 256K: 58.0% of Kimi Allegretto (58.0% / 5h, 11.0% / 1w) per run. Its weekly limit holds about 5 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-6 Sol | Kimi K3 256K | Advantage |
|---|---|---|---|
| Capability | 51% | 24% | +27% (GPT-6 Sol leads) |
| Median task time | 3m 4s | 6m 33s | 3m 28s faster (GPT-6 Sol leads) |
| Approx. task cost | $0.018 / task | $0.269 / task | $0.251 / task lower (GPT-6 Sol leads) |
GPT-6 Sol: 0.4% of ChatGPT Plus (2.4% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 6 of the week's 33.6 5h windows. Kimi K3 256K: 14.0% of Kimi Allegretto (14.0% / 5h, 3.0% / 1w) per good solve. Its weekly limit holds about 5 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
Grades and deltas are comparable only within a suite version. See methodology.
Frequently asked questions
Which is better for coding, GPT-6 Sol or Kimi K3 256K?
Kimi K3 256K clears higher: tier 2 of 5 versus tier 1 for GPT-6 Sol on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-23.
Which is cheaper per task, GPT-6 Sol or Kimi K3 256K?
GPT-6 Sol used 5% of ChatGPT Plus's weekly limit per pass, $0.012 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1% of ChatGPT Pro 5x's weekly limit (est, about $0.012 per task). Kimi K3 256K used 34% of Kimi Allegretto's weekly limit per pass, $0.161 per task at the listed price. Per task, GPT-6 Sol is about 13x cheaper ($0.012 vs $0.161).
What do GPT-6 Sol and Kimi K3 256K cost a month?
GPT-6 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). Kimi K3 256K runs on Kimi Allegretto at $39/month (public price as of 2026-07-20).