Claude Haiku 4.5 vs GPT-6 Luna
GPT-6 Luna leads overall, D to F. GPT-6 Luna is about 5.0x cheaper per task. By suite, real-world issues is even at D+ and GPT-6 Luna takes spec planning (C- to F). The data gives no reason to pick Claude Haiku 4.5 over GPT-6 Luna this week.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: GPT-6 Luna vs Claude Haiku 4.5
GPT-6 Luna leads overall, D to F. By suite: real-world issues is even at D+ (50% vs 50% capability); GPT-6 Luna takes spec planning, C- to F (61% vs 19% capability); vibe coding is even at F (23% vs 33% capability). Claude Haiku 4.5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 per task at the listed price. GPT-6 Luna used 1% of ChatGPT Plus's weekly limit per pass, $0.002 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~0.2% of ChatGPT Pro 5x's weekly limit (est, about $0.002 per task). Per task, GPT-6 Luna is about 5.0x cheaper ($0.002 vs $0.012). GPT-6 Luna is faster on real-world issues: a median task takes 1m 0s against 3m 39s. Both finished every task on it. The data gives no reason to pick Claude Haiku 4.5 over GPT-6 Luna this week.
Changed since W32: Claude Haiku 4.5: real-world issues F to D+.
| Dimension | Claude Haiku 4.5 | GPT-6 Luna | Advantage |
|---|---|---|---|
| Capability | 50% | 50% | Even |
| Median task time | 3m 39s | 1m 0s | 2m 39s faster (GPT-6 Luna leads) |
| Approx. task cost | $0.015 / task | $0.003 / task | $0.012 / task lower (GPT-6 Luna leads) |
Claude Haiku 4.5: 13.0% of Claude Max 5x (13.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. GPT-6 Luna: 1.0% of ChatGPT Plus (1.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 6 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 | Claude Haiku 4.5 | GPT-6 Luna | Advantage |
|---|---|---|---|
| Capability | 19% | 61% | +41% (GPT-6 Luna leads) |
| Median task time | 1m 56s | 1m 8s | 48s faster (GPT-6 Luna leads) |
| Approx. task cost | $0.002 / task | <$0.011 / task | $0.010 / task lower (Claude Haiku 4.5 leads) |
Claude Haiku 4.5: 1.0% of Claude Max 5x (1.0% / 5h) per run. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. GPT-6 Luna: under 1% of ChatGPT Plus per run. Its weekly limit holds about 6 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 | Claude Haiku 4.5 | GPT-6 Luna | Advantage |
|---|---|---|---|
| Capability | 23% | 33% | +10% (GPT-6 Luna leads) |
| Median task time | 3m 36s | 1m 37s | 1m 59s faster (GPT-6 Luna leads) |
| Approx. task cost | $0.057 / task | not measured | - |
Claude Haiku 4.5: 2.0% of Claude Max 5x (2.0% / 5h, 0.3% / 1w) per good solve. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. GPT-6 Luna: under 1% of ChatGPT Plus (0.4% / 5h) per good solve. Its weekly limit holds about 6 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, Claude Haiku 4.5 or GPT-6 Luna?
They are even on our ladder: both clear tier 2 of 5 at 50% capability on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-21.
Which is cheaper per task, Claude Haiku 4.5 or GPT-6 Luna?
Claude Haiku 4.5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 per task at the listed price. GPT-6 Luna used 1% of ChatGPT Plus's weekly limit per pass, $0.002 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~0.2% of ChatGPT Pro 5x's weekly limit (est, about $0.002 per task). Per task, GPT-6 Luna is about 5.0x cheaper ($0.002 vs $0.012).
What do Claude Haiku 4.5 and GPT-6 Luna cost a month?
Claude Haiku 4.5 runs on Claude Max 5x at $100/month (public price as of 2026-07-20). GPT-6 Luna runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).