Model vs model
Claude Opus 5.5 vs GPT-6 Astra
Claude Opus 5.5 and GPT-6 Astra are both in llmwise. What each gets on every plan, what it reads, how it's served and what happens when its provider fails, from the catalog and the code that runs them.
Model prices and specs checked against OpenRouter's Claude Opus 5.5 page, OpenRouter's GPT-6 Astra page. Updated .
Short answer
Claude Opus 5.5 gets twice as many messages: up to 62 messages a month on Pro, against up to 31 messages a month for GPT-6 Astra. Otherwise, only Claude Opus 5.5 can be passed to another model by its maker's safety system. In our test runs, Claude Opus 5.5 passed 49 of the 50 prompts both answered and GPT-6 Astra 48; 3 prompts split them, most on customer support (5 to 3).
Claude Opus 5.5 vs GPT-6 Astra, prompt by prompt
Every prompt Claude Opus 5.5 and GPT-6 Astra both answered, compared directly, their biggest differences first. One run each, through OpenRouter: a wait depends on the provider and the load that day, so a lead under 10% counts as close.
Of the 50 prompts both answered, both passed 47, only Claude Opus 5.5 passed 2, only GPT-6 Astra passed 1, and neither passed 0. Claude Opus 5.5 answered sooner on 4 of the 50 and GPT-6 Astra on 45; the rest were within 10% of each other. The 50 replies cost $0.5360 on Claude Opus 5.5 and $0.5847 on GPT-6 Astra: about the same for both.
The 3 prompts only one of Claude Opus 5.5 and GPT-6 Astra passed
Argue both sides of free buses (writing): GPT-6 Astra passed and Claude Opus 5.5 didn't. Claude Opus 5.5: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 93 words, over the 90 allowed. GPT-6 Astra: Graded 4.7 of 5 on average (lowest 4).
A late order (customer support): Claude Opus 5.5 passed and GPT-6 Astra didn't. Claude Opus 5.5: Graded 4.3 of 5 on average (lowest 3). GPT-6 Astra: Graded 3.7 of 5 on average (lowest 1).
A frustrated customer (customer support): Claude Opus 5.5 passed and GPT-6 Astra didn't. Claude Opus 5.5: Graded 4.0 of 5 on average (lowest 3). GPT-6 Astra: Graded 3.3 of 5 on average (lowest 2).
Job by job, the widest gaps first
Customer support: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 3 of 5. GPT-6 Astra answered 1.7× sooner at the median, 6.4 s against 3.8 s. They cost about the same, $0.0540 against $0.0578 for the 5 replies. Claude Opus 5.5's replies ran 120% longer, in tokens of reply, thinking not counted.
Writing: Claude Opus 5.5 passed 4 of 5 and GPT-6 Astra 5 of 5. GPT-6 Astra answered 1.7× sooner at the median, 8.2 s against 4.8 s. GPT-6 Astra cost 1.7× less, $0.0923 against $0.0556 for the 5 replies. Claude Opus 5.5's replies ran 88% longer, in tokens of reply, thinking not counted.
Math: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 5 of 5. GPT-6 Astra answered 1.5× sooner at the median, 3.9 s against 2.6 s. Claude Opus 5.5 cost 1.4× less, $0.0298 against $0.0427 for the 5 replies. Claude Opus 5.5's replies ran 61% longer, in tokens of reply, thinking not counted.
Agents and tool use: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 5 of 5. GPT-6 Astra answered 1.7× sooner at the median, 3.1 s against 1.9 s. Claude Opus 5.5 cost 1.3× less, $0.0252 against $0.0340 for the 5 replies. Claude Opus 5.5's replies ran 64% longer, in tokens of reply, thinking not counted.
Coding: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 5 of 5. Claude Opus 5.5 answered 1.1× sooner at the median, 7.2 s against 8.2 s. Claude Opus 5.5 cost 1.3× less, $0.0853 against $0.1117 for the 5 replies. Claude Opus 5.5's replies ran 100% longer, in tokens of reply, thinking not counted.
Data analysis: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 5 of 5. GPT-6 Astra answered 1.4× sooner at the median, 4.6 s against 3.3 s. Claude Opus 5.5 cost 1.2× less, $0.0654 against $0.0772 for the 5 replies. Claude Opus 5.5's replies ran 107% longer, in tokens of reply, thinking not counted.
Translation: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 5 of 5. GPT-6 Astra answered 1.4× sooner at the median, 5.5 s against 3.8 s. Claude Opus 5.5 cost 1.2× less, $0.0540 against $0.0628 for the 5 replies. Claude Opus 5.5's replies ran 119% longer, in tokens of reply, thinking not counted.
Summarization: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 5 of 5. GPT-6 Astra answered 1.3× sooner at the median, 3.7 s against 2.9 s. Claude Opus 5.5 cost 1.1× less, $0.0475 against $0.0546 for the 5 replies. Claude Opus 5.5's replies ran 62% longer, in tokens of reply, thinking not counted.
RAG and answering from documents: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 5 of 5. GPT-6 Astra answered 1.7× sooner at the median, 2.9 s against 1.7 s. They cost about the same, $0.0367 against $0.0394 for the 5 replies. Claude Opus 5.5's replies ran 164% longer, in tokens of reply, thinking not counted.
SQL: Claude Opus 5.5 passed 5 of 5 and GPT-6 Astra 5 of 5. GPT-6 Astra answered 2.0× sooner at the median, 4.3 s against 2.2 s. They cost about the same, $0.0459 against $0.0491 for the 5 replies. Claude Opus 5.5's replies ran 125% longer, in tokens of reply, thinking not counted.
All 50 prompts: who passed, who answered sooner, who cost less
| Prompt | Result | Sooner | Cheaper |
|---|---|---|---|
| Turn a title into a URL slug | Both passed | GPT-6 Astra, 1.5×took 3.1 s and 2.1 s | Claude Opus 5.5, 1.5×cost $0.0055 and $0.0084 |
| Parse a duration like “1h 30m” | Both passed | Claude Opus 5.5, 1.1×took 7.2 s and 8.2 s | Claude Opus 5.5, 2.1×cost $0.0112 and $0.0235 |
| Merge overlapping intervals | Both passed | GPT-6 Astra, 1.4×took 3.7 s and 2.6 s | Claude Opus 5.5, 1.4×cost $0.0077 and $0.0108 |
| Evaluate an arithmetic expression, no eval | Both passed | GPT-6 Astra, 1.3×took 15.8 s and 12.0 s | Claude Opus 5.5, 1.1×cost $0.0336 and $0.0375 |
| Parse CSV with quoted fields | Both passed | GPT-6 Astra, 1.3×took 11.9 s and 9.1 s | Claude Opus 5.5, 1.2×cost $0.0273 and $0.0314 |
| Announce a second bakery shop on LinkedIn | Both passed | GPT-6 Astra, 1.8×took 8.7 s and 4.8 s | GPT-6 Astra, 1.6×cost $0.0175 and $0.0111 |
| Rewrite corporate jargon in plain words | Both passed | Claude Opus 5.5, 1.2×took 5.1 s and 6.0 s | Claude Opus 5.5, 1.8×cost $0.0078 and $0.0145 |
| Decline a meeting and offer two times | Both passed | GPT-6 Astra, 1.2×took 4.1 s and 3.3 s | Claude Opus 5.5, 1.4×cost $0.0056 and $0.0079 |
| A product announcement with five rules | Both passed | GPT-6 Astra, 2.5×took 8.2 s and 3.3 s | GPT-6 Astra, 2.0×cost $0.0170 and $0.0084 |
| Argue both sides of free buses | Only GPT-6 Astra | GPT-6 Astra, 3.1×took 22.5 s and 7.2 s | GPT-6 Astra, 3.2×cost $0.0443 and $0.0137 |
| A discount, then sales tax | Both passed | GPT-6 Astra, 1.5×took 2.7 s and 1.9 s | Claude Opus 5.5, 1.7×cost $0.0037 and $0.0063 |
| Pens at 3 for $4 | Both passed | GPT-6 Astra, 2.3×took 5.3 s and 2.4 s | Closecost $0.0084 and $0.0082 |
| Compound interest over three years | Both passed | GPT-6 Astra, 1.4×took 3.7 s and 2.7 s | Claude Opus 5.5, 1.7×cost $0.0043 and $0.0072 |
| Four-digit numbers whose digits sum to 9 | Both passed | GPT-6 Astra, 1.3×took 4.7 s and 3.8 s | Claude Opus 5.5, 1.6×cost $0.0077 and $0.0122 |
| The highest of three dice is a 5 | Both passed | GPT-6 Astra, 1.5×took 3.9 s and 2.6 s | Claude Opus 5.5, 1.5×cost $0.0057 and $0.0088 |
| An article in three bullets | Both passed | GPT-6 Astra, 1.6×took 8.1 s and 5.0 s | GPT-6 Astra, 1.2×cost $0.0171 and $0.0143 |
| An email thread in one sentence | Both passed | GPT-6 Astra, 1.4×took 2.6 s and 1.9 s | Claude Opus 5.5, 1.6×cost $0.0044 and $0.0071 |
| Decisions and action items from a meeting | Both passed | GPT-6 Astra, 1.8×took 5.8 s and 3.3 s | Closecost $0.0118 and $0.0123 |
| A quarterly memo for the CEO | Both passed | GPT-6 Astra, 1.2×took 3.5 s and 2.9 s | Claude Opus 5.5, 1.6×cost $0.0075 and $0.0118 |
| A study with a negative result | Both passed | GPT-6 Astra, 1.6×took 3.7 s and 2.3 s | Claude Opus 5.5, 1.4×cost $0.0066 and $0.0091 |
| The region with the most revenue | Both passed | GPT-6 Astra, 1.3×took 4.1 s and 3.3 s | Claude Opus 5.5, 1.6×cost $0.0087 and $0.0136 |
| Average order value in August | Both passed | GPT-6 Astra, 1.8×took 4.4 s and 2.5 s | Closecost $0.0107 and $0.0104 |
| Revenue change from July to August | Both passed | GPT-6 Astra, 1.4×took 5.1 s and 3.6 s | Claude Opus 5.5, 1.2×cost $0.0120 and $0.0150 |
| A median, filtered two ways | Both passed | GPT-6 Astra, 2.3×took 4.6 s and 2.0 s | Claude Opus 5.5, 1.1×cost $0.0079 and $0.0090 |
| Correlation between ad spend and sign-ups | Both passed | GPT-6 Astra, 1.3×took 11.5 s and 8.8 s | Claude Opus 5.5, 1.1×cost $0.0261 and $0.0294 |
| A late order | Only Claude Opus 5.5 | GPT-6 Astra, 1.9×took 7.8 s and 4.1 s | Closecost $0.0114 and $0.0123 |
| A return inside the window | Both passed | GPT-6 Astra, 1.8×took 4.4 s and 2.4 s | Claude Opus 5.5, 1.2×cost $0.0074 and $0.0087 |
| A frustrated customer | Only Claude Opus 5.5 | GPT-6 Astra, 1.7×took 6.4 s and 3.8 s | Closecost $0.0111 and $0.0120 |
| A refund request outside the window | Both passed | GPT-6 Astra, 1.2×took 6.1 s and 5.0 s | Claude Opus 5.5, 1.3×cost $0.0106 and $0.0137 |
| A message with a planted instruction | Both passed | GPT-6 Astra, 2.9×took 7.9 s and 2.7 s | GPT-6 Astra, 1.2×cost $0.0136 and $0.0112 |
| A delivery message into Spanish | Both passed | Claude Opus 5.5, 1.2×took 3.2 s and 3.8 s | Claude Opus 5.5, 1.8×cost $0.0064 and $0.0116 |
| A product description into French | Both passed | GPT-6 Astra, 2.3×took 5.8 s and 2.5 s | GPT-6 Astra, 1.2×cost $0.0113 and $0.0093 |
| A meeting note into German | Both passed | Claude Opus 5.5, 1.1×took 5.5 s and 6.1 s | Claude Opus 5.5, 1.9×cost $0.0096 and $0.0180 |
| Idioms into natural Japanese | Both passed | GPT-6 Astra, 1.1×took 3.6 s and 3.2 s | Claude Opus 5.5, 1.6×cost $0.0062 and $0.0100 |
| A lease clause into Brazilian Portuguese | Both passed | GPT-6 Astra, 2.1×took 11.4 s and 5.3 s | GPT-6 Astra, 1.5×cost $0.0204 and $0.0139 |
| Customers in one country | Both passed | GPT-6 Astra, 1.7×took 2.5 s and 1.5 s | Claude Opus 5.5, 1.3×cost $0.0048 and $0.0061 |
| Count orders by status | Both passed | GPT-6 Astra, 1.7×took 2.5 s and 1.4 s | Claude Opus 5.5, 1.2×cost $0.0049 and $0.0058 |
| Revenue by category | Both passed | GPT-6 Astra, 2.0×took 4.3 s and 2.2 s | Closecost $0.0092 and $0.0091 |
| Every customer, even those without orders | Both passed | GPT-6 Astra, 1.7×took 5.0 s and 2.9 s | Closecost $0.0094 and $0.0091 |
| Monthly revenue with a running total | Both passed | GPT-6 Astra, 1.4×took 7.8 s and 5.8 s | Closecost $0.0176 and $0.0190 |
| A fact from one section | Both passed | GPT-6 Astra, 1.9×took 2.5 s and 1.3 s | Claude Opus 5.5, 1.4×cost $0.0054 and $0.0073 |
| Core hours and start times | Both passed | GPT-6 Astra, 1.1×took 2.6 s and 2.4 s | Claude Opus 5.5, 1.5×cost $0.0054 and $0.0080 |
| Two sections in one answer | Both passed | GPT-6 Astra, 1.7×took 2.9 s and 1.7 s | Claude Opus 5.5, 1.5×cost $0.0053 and $0.0082 |
| A later amendment changes the answer | Both passed | GPT-6 Astra, 3.7×took 7.7 s and 2.1 s | GPT-6 Astra, 1.7×cost $0.0148 and $0.0086 |
| A question the handbook doesn't answer | Both passed | GPT-6 Astra, 2.4×took 3.4 s and 1.4 s | Claude Opus 5.5, 1.3×cost $0.0057 and $0.0073 |
| Pick the tool and work out the date | Both passed | GPT-6 Astra, 1.9×took 2.7 s and 1.4 s | Claude Opus 5.5, 1.5×cost $0.0041 and $0.0060 |
| Convert a currency | Both passed | Closetook 2.8 s and 2.9 s | Claude Opus 5.5, 1.4×cost $0.0041 and $0.0059 |
| Book a meeting from a sentence | Both passed | GPT-6 Astra, 3.9×took 7.2 s and 1.9 s | Claude Opus 5.5, 1.3×cost $0.0059 and $0.0077 |
| Search, but don't book | Both passed | GPT-6 Astra, 2.1×took 3.1 s and 1.5 s | Claude Opus 5.5, 1.5×cost $0.0046 and $0.0069 |
| Two calls with a unit conversion | Both passed | GPT-6 Astra, 1.5×took 3.4 s and 2.3 s | Claude Opus 5.5, 1.2×cost $0.0064 and $0.0074 |
Claude Opus 5.5 vs GPT-6 Astra in our test runs
Claude Opus 5.5 and GPT-6 Astra on the same prompts, job by job: how many replies passed their check.
Based on 100 of our test runs on , through OpenRouter with the app's own prompt and settings. Updated .
| Job | Claude Opus 5.5 | GPT-6 Astra |
|---|---|---|
| Coding | 5 of 5 | 5 of 5 |
| Writing | 4 of 5 | 5 of 5 |
| Math | 5 of 5 | 5 of 5 |
| Summarization | 5 of 5 | 5 of 5 |
| Data analysis | 5 of 5 | 5 of 5 |
| Customer support | 5 of 5 | 3 of 5 |
| Translation | 5 of 5 | 5 of 5 |
| SQL | 5 of 5 | 5 of 5 |
| RAG and answering from documents | 5 of 5 | 5 of 5 |
| Agents and tool use | 5 of 5 | 5 of 5 |
| All jobs | 49 of 50 · 1 message each · $0.0107 a reply | 48 of 50 · 1 message each · $0.0117 a reply |
The same prompts, sent to both through llmwise's own pipeline and checked the same way: five for each job. A bold count is the one that passed more. Messages: what each reply counted as on Pro. Cost: what OpenRouter charged us per reply, on average. Every prompt, and how it's scored.
Where they differed most, customer support: both replies to a prompt only one of them passed.
An everyday prompt: “A late order”, in full.
Claude Opus 5.5
Passed: Graded 4.3 of 5 on average (lowest 3).
Hi there, I'm sorry your rain jacket hasn't arrived yet. Standard delivery usually takes 3 to 5 business days, so your order is running late, and I understand how frustrating that is. Could you reply with your order number? I'll check the tracking details with our carrier and let you know exactly where your package is and when to expect it. If your order ends up more than 7 business days past its expected delivery date, you'll get free express shipping on your next order. Thanks for your patience, and I'll get back to you as soon as I have an update. Sam, Northwind support
715 tokens in, 395 out (209 of them reasoning) · 7.8 s · $0.0114 · 1 message on Pro · answered by anthropic/claude-opus-5.5 via Claude Platform on AWS ·
GPT-6 Astra
Failed: Graded 3.7 of 5 on average (lowest 1).
I’m sorry your rain jacket hasn’t arrived yet. Standard delivery normally takes 3–5 business days, so this is longer than expected. Please send your order number so we can check the tracking and look into the delay. If you received a shipping confirmation, its tracking link may also show the latest update. Sam, Northwind support
511 tokens in, 143 out (69 of them reasoning) · 4.1 s · $0.0123 · 1 message on Pro · answered by openai/gpt-6-astra via OpenAI ·
Claude Opus 5.5 and GPT-6 Astra on every plan
Whether the one-time free trial reaches each model, then each paid plan's messages on it.
| Plan | Price | Claude Opus 5.5 | GPT-6 Astra |
|---|---|---|---|
| Free | $0 | Not in the trial | Not in the trial |
| Plus | $10 a month | Up to 31 a month | Not on Plus |
| Pro | $20 a month | Up to 62 a month | Up to 31 a month |
| Max | $50 a month | Up to 200 a month | Up to 100 a month |
| Ultra | $100 a month | Up to 450 a month | Up to 225 a month |
| Studio | $200 a month | Up to 1,000 a month | Up to 500 a month |
Prices don't include tax, which is added where it applies and shown before you pay. A paid plan's month is one allowance shared by every model, so each monthly count is the most you get if all of it goes to that model. It renews each billing period; everyday models refill daily at 00:00 UTC. Long chats count more per reply. How pricing works.
Every limit is published. Paid plans also have a monthly fair-use limit on AI cost: Plus $3.75, Pro $7.50, Max $20, Ultra $42, Studio $85. Using every message on your plan at typical sizes stays under it; very large messages and heavy research use it faster. Every limit, explained.
What differs
Messages on Pro
Claude Opus 5.5 gets twice as many messages: up to 62 messages a month on Pro, against up to 31 messages a month for GPT-6 Astra.
Context window
Claude Opus 5.5 takes up to 1M tokens; GPT-6 Astra up to 1.05M tokens. A chat in llmwise holds up to 200k tokens, which fits in either, so the difference shows only through each maker's own API.
Images and PDFs
Both read images. Both take a PDF as the whole file, pages and all.
On Free
Neither is in the free trial: Claude Opus 5.5 needs a paid plan and GPT-6 Astra needs Pro or a higher plan.
Where messages go
Claude Opus 5.5: Sent to Anthropic directly. GPT-6 Astra: Sent to OpenAI directly.
Fact by fact
| Fact | Claude Opus 5.5 | GPT-6 Astra |
|---|---|---|
| Context window | 1M tokens | 1.05M tokens |
| Reads images | Yes | Yes |
| PDFs | Whole file | Whole file |
| Reasoning | Yes | Yes |
| API price (October 2026) | $4.00 in / $20.00 out per million tokens | $10.00 in / $50.00 out per million tokens |
| A typical message at API prices (4,000 tokens in, 700 out) | $0.0300 | $0.0750 |
| A $10 top-up adds | 50 messages | 25 messages |
| Where a message goes | Sent to Anthropic directly. | Sent to OpenAI directly. |
| If the provider fails | If Anthropic fails before the reply starts (an overload, a server error, a dropped connection), llmwise sends the same request to Claude Opus 5.5 through OpenRouter instead. | If OpenAI fails before the reply starts (an overload, a server error, a dropped connection), llmwise sends the same request to GPT-6 Astra through OpenRouter instead. |
| Anthropic's safety fallback | Anthropic's safety system can pass a Claude Opus 5.5 message to another Claude model. The reply then names the model that answered and says what you were charged for. | Doesn't apply |
Claude Opus 5.5 or GPT-6 Astra?
From the facts above and our test runs: the rest is how their answers suit your work, which one chat can show you.
Pick Claude Opus 5.5: more messages for the money, up to 62 messages a month on Pro.
Each model's page, the families, and other pairs
Claude Opus 5.5 vs GPT-6 Astra is one pair of models. The page below covers the whole families.
- Claude Opus 5.5: price, limits and messages on every plan
- GPT-6 Astra: price, limits and messages on every plan
- Claude vs ChatGPT
- Claude Fable 5.1 vs Claude Opus 5.5
- Claude Opus 5.5 vs Claude Sonnet 5
- Claude Opus 5.5 vs Claude Sonnet 5.5
- Claude Fable 5.1 vs GPT-6 Astra
- GPT-6 Astra vs GPT-6.1 Sol
- Gemini 4 Argon vs GPT-6 Astra
- Every model-vs-model page
Claude Opus 5.5 is a Claude model; GPT-6 Astra is a GPT model.
Questions
Is Claude Opus 5.5 or GPT-6 Astra cheaper in llmwise?
Claude Opus 5.5 gets twice as many messages: up to 62 messages a month on Pro, against up to 31 messages a month for GPT-6 Astra. Every paid plan's monthly allowance is shared by the models on it, so each count is the most you get if it all goes to that model.
Can I try Claude Opus 5.5 and GPT-6 Astra for free?
Neither is in the free trial of 5 messages: Claude Opus 5.5 needs a paid plan and GPT-6 Astra needs Pro or a higher plan.
Which has the bigger context window, Claude Opus 5.5 or GPT-6 Astra?
GPT-6 Astra: 1.05M tokens, against 1M tokens. A chat in llmwise holds up to 200k tokens, which fits in either, so the difference shows only through each maker's own API.
Can I use Claude Opus 5.5 and GPT-6 Astra in the same chat?
Yes. Pick Claude Opus 5.5 for one message and GPT-6 Astra for the next; the second sees the whole chat, including the first one's answer.
Which did better in your test runs, Claude Opus 5.5 or GPT-6 Astra?
On the same 50 prompts, run on September 27, 2026, Claude Opus 5.5 passed 49 and GPT-6 Astra passed 48. The table on this page has each job, and every reply is published.
Claude, GPT, Gemini, DeepSeek, Grok, Kimi, GLM, and Mistral, in one chat.
See what a message costs before you send it. Free is 5 messages to try; sign in with an email link, no password or card.