Claude Opus 5 vs Claude Opus 5.5 vs ChatGPT Astra: Price, Benchmarks, and Latency

Claude Opus 5, Claude Opus 5.5, and ChatGPT Astra are three large language models that differ in price, benchmark performance, and latency. This article compares them using the latest publicly available vendor figures and third-party analyses, highlighting where the evidence is…

Key takeaways

Claude Opus 5.5 is reported to be about 40% cheaper than Opus 5 when comparing medium vs high load settings, and about 60% cheaper than ChatGPT Astra, but these figures come from different contexts and lack absolute pricing.
On an unspecified benchmark, Opus 5.5 scored 59.6%, described as on par with Astra.
According to an Anthropic comparison table, Opus 5.5 outscores Astra on two coding evaluations, while Astra leads on science.
Astra appears strong on computer use, cyber, and math.
Latency data is limited and contains an internally inconsistent claim; Opus 5.5 is said to have lower latency than Opus 5, but the exact difference is unclear.
Direct head-to-head comparisons are unavailable; all figures are relative and tied to unspecified workloads.

Price

The most concrete cost claim is that Opus 5.5 is "about 40% cheaper" than Opus 5, but this compares running Opus 5.5 at medium against Opus 5 at high (https://note.com/takuma_hayakawa/n/ne9f061f5a983?hl=en). A separate source states Opus 5.5 is about 60% cheaper than ChatGPT Astra (https://www.orcarouter.ai/compare/claude-opus-5.5-vs-gpt-6-astra). No absolute per-token prices are provided, and the baselines differ, so the savings may not hold for all workloads.

Benchmark performance

One source reports that Opus 5.5 achieved 59.6% on an unspecified benchmark, described as a level on par with Astra (same note by Hayakawa). An Anthropic comparison table, as referenced by myclaw.ai, gives Opus 5.5 higher scores than Astra on two coding evaluations, while Astra leads on the science row (https://myclaw.ai/zh-TW/blog/claude-opus-5-5-vs-gpt-6-astra). A separate analysis on Medium notes that Astra looks very strong against Claude on computer use, cyber, and math (https://medium.com/data-science-collective/gpt-6-astra-vs-claude-and-the-open-models-what-the-benchmarks-dont-tell-you-7f5ed78c8885). These results suggest a trade-off: Opus 5.5 may have an edge in coding, while Astra may be stronger in science and related domains.

Latency

A third-party comparison claims that Opus 5.5 leads on both cost and median latency, but the snippet contains the phrase "8% faster than Claude Opus 5.5", which is internally inconsistent and prevents a clear interpretation (https://www.orcarouter.ai/compare/claude-opus-5.5-vs-gpt-6-astra). Without clarification, it is impossible to determine whether this refers to a comparison with Opus 5 or is a typographical error. No absolute latency figures or test conditions are given, so latency differences should be treated as indicative rather than definitive.

Evidence gaps

The available evidence has significant limitations:

No source provides direct, like-for-like benchmark comparisons between all three models.
Absolute pricing, release dates, and hardware configurations are absent.
The benchmark score (59.6%) is unspecified as to dataset and metric.
The latency claim contains an internal contradiction.
Relative cost figures are tied to specific load settings that may not generalize.

Which to pick

If your priority is cost and you can accept the reported savings, Opus 5.5 appears cheaper than both Opus 5 (under the compared settings) and ChatGPT Astra. If coding performance is the main criterion, Opus 5.5 leads on two evaluations. If science or computer use/cyber/math strength matters more, Astra may be the better choice. However, because the evidence is fragmentary and inconsistent, a definitive ranking is not possible. Before committing, seek out current, transparent pricing and, if possible, run your own workload on each model.

Meta description: Compare Claude Opus 5, Opus 5.5, and ChatGPT Astra on price, benchmarks, and latency. See where evidence supports a winner and where gaps remain.