Claude Opus 5 vs GPT-6 Astra
Claude Opus 5 was superseded by Claude Opus 5.5. The grades below are the last ones measured, so read them as history rather than as this week's board. See the current roster.
Both grade C overall. Claude Opus 5 is about 2.2x cheaper per task. By suite, Claude Opus 5 takes real-world issues (C- to D) and GPT-6 Astra takes spec planning (C+ to C). Both agents run the same private suite cut headless through their own tools, each on its own subscription.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 Astra vs Claude Opus 5
Both grade C overall. By suite: Claude Opus 5 takes real-world issues, C- to D (57% vs 43% capability); GPT-6 Astra takes spec planning, C+ to C (74% vs 66% capability); vibe coding is even at C+ (72% vs 74% capability). Claude Opus 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. GPT-6 Astra used 22% of ChatGPT Plus's weekly limit per pass, $0.053 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~4.4% of ChatGPT Pro 5x's weekly limit (est, about $0.053 per task). Per task, Claude Opus 5 is about 2.2x cheaper ($0.024 vs $0.053). Claude Opus 5 is faster on real-world issues: a median task takes 1m 56s against 2m 13s. Both finished every task on it.
Changed since W32: Claude Opus 5: real-world issues usage 3% to 1% of the weekly limit; GPT-6 Astra has one graded week under this version (W40).
| Dimension | Claude Opus 5 | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 57% | 43% | +13% (Claude Opus 5 leads) |
| Median task time | 1m 56s | 2m 13s | 18s faster (Claude Opus 5 leads) |
| Approx. task cost | $0.015 / task | $0.052 / task | $0.037 / task lower (Claude Opus 5 leads) |
Claude Opus 5: 21.0% of Claude Max 5x (21.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. GPT-6 Astra: 17.0% of ChatGPT Plus (112.0% / 5h, 17.0% / 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 Opus 5 | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 66% | 74% | +9% (GPT-6 Astra leads) |
| Median task time | 2m 9s | 3m 5s | 57s faster (Claude Opus 5 leads) |
| Approx. task cost | $0.057 / task | $0.057 / task | Even |
Claude Opus 5: 6.0% of Claude Max 5x (6.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. GPT-6 Astra: 5.0% of ChatGPT Plus (27.0% / 5h, 5.0% / 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 Opus 5 | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 72% | 74% | +3% (GPT-6 Astra leads) |
| Median task time | 2m 51s | 2m 40s | 12s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.011 / task | $0.046 / task | $0.035 / task lower (Claude Opus 5 leads) |
Claude Opus 5: 1.6% of Claude Max 5x (1.6% / 5h) per good solve. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. GPT-6 Astra: 1.0% of ChatGPT Plus (7.2% / 5h, 1.0% / 1w) 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 Opus 5 or GPT-6 Astra?
Both clear tier 2 of 5, but Claude Opus 5 scores higher on capability: 57% versus 43% on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-21.
Which is cheaper per task, Claude Opus 5 or GPT-6 Astra?
Claude Opus 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. GPT-6 Astra used 22% of ChatGPT Plus's weekly limit per pass, $0.053 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~4.4% of ChatGPT Pro 5x's weekly limit (est, about $0.053 per task). Per task, Claude Opus 5 is about 2.2x cheaper ($0.024 vs $0.053).
What do Claude Opus 5 and GPT-6 Astra cost a month?
Claude Opus 5 runs on Claude Max 5x at $100/month (public price as of 2026-07-27). GPT-6 Astra runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).