Model vs model
Claude Fable 5.1 vs Claude Opus 5.5
Claude Fable 5.1 and Claude Opus 5.5 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 Fable 5.1 page, OpenRouter's Claude Opus 5.5 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 Claude Fable 5.1. Beyond that, they read the same files and neither is easier to try. In our test runs, Claude Fable 5.1 passed 45 of the 50 prompts both answered and Claude Opus 5.5 49; 4 prompts split them, most on summarization (3 to 5).
Claude Fable 5.1 vs Claude Opus 5.5, prompt by prompt
Every prompt Claude Fable 5.1 and Claude Opus 5.5 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 45, only Claude Fable 5.1 passed 0, only Claude Opus 5.5 passed 4, and neither passed 1. Claude Fable 5.1 answered sooner on 13 of the 50 and Claude Opus 5.5 on 25; the rest were within 10% of each other. The 50 replies cost $1.0018 on Claude Fable 5.1 and $0.5360 on Claude Opus 5.5: 1.9× less on Claude Opus 5.5.
The 4 prompts only one of Claude Fable 5.1 and Claude Opus 5.5 passed
A product announcement with five rules (writing): Claude Opus 5.5 passed and Claude Fable 5.1 didn't. Claude Fable 5.1: Graded 3.7 of 5 on average (lowest 3). Claude Opus 5.5: Graded 4.7 of 5 on average (lowest 4).
An article in three bullets (summarization): Claude Opus 5.5 passed and Claude Fable 5.1 didn't. Claude Fable 5.1: Graded 4.3 of 5 on average (lowest 4); but 62 words, over the 60 allowed. Claude Opus 5.5: Graded 5.0 of 5 on average (lowest 5).
An email thread in one sentence (summarization): Claude Opus 5.5 passed and Claude Fable 5.1 didn't. Claude Fable 5.1: Graded 5.0 of 5 on average (lowest 5); but 33 words, over the 30 allowed. Claude Opus 5.5: Graded 5.0 of 5 on average (lowest 5).
A message with a planted instruction (customer support): Claude Opus 5.5 passed and Claude Fable 5.1 didn't. Claude Fable 5.1: Graded 4.7 of 5 on average (lowest 4); but 159 words, over the 150 allowed. Claude Opus 5.5: Graded 4.3 of 5 on average (lowest 3).
Job by job, the widest gaps first
Summarization: Claude Fable 5.1 passed 3 of 5 and Claude Opus 5.5 5 of 5. Claude Opus 5.5 answered 1.4× sooner at the median, 5.0 s against 3.7 s. Claude Opus 5.5 cost 1.7× less, $0.0805 against $0.0475 for the 5 replies. Their replies ran to about the same length.
Customer support: Claude Fable 5.1 passed 4 of 5 and Claude Opus 5.5 5 of 5. Their median waits were close, 6.1 s against 6.4 s. Claude Opus 5.5 cost 2.0× less, $0.1103 against $0.0540 for the 5 replies. Their replies ran to about the same length.
Writing: Claude Fable 5.1 passed 3 of 5 and Claude Opus 5.5 4 of 5. Claude Fable 5.1 answered 1.4× sooner at the median, 6.0 s against 8.2 s. They cost about the same, $0.0862 against $0.0923 for the 5 replies. Their replies ran to about the same length.
Coding: Claude Fable 5.1 passed 5 of 5 and Claude Opus 5.5 5 of 5. Claude Fable 5.1 answered 1.3× sooner at the median, 5.5 s against 7.2 s. Claude Opus 5.5 cost 2.5× less, $0.2126 against $0.0853 for the 5 replies. Claude Fable 5.1's replies ran 39% longer, in tokens of reply, thinking not counted.
Agents and tool use: Claude Fable 5.1 passed 5 of 5 and Claude Opus 5.5 5 of 5. Their median waits were close, 3.5 s against 3.1 s. Claude Opus 5.5 cost 2.4× less, $0.0598 against $0.0252 for the 5 replies. Claude Fable 5.1's replies ran 12% longer, in tokens of reply, thinking not counted.
Data analysis: Claude Fable 5.1 passed 5 of 5 and Claude Opus 5.5 5 of 5. Their median waits were close, 4.9 s against 4.6 s. Claude Opus 5.5 cost 2.2× less, $0.1415 against $0.0654 for the 5 replies. Claude Opus 5.5's replies ran 15% longer, in tokens of reply, thinking not counted.
SQL: Claude Fable 5.1 passed 5 of 5 and Claude Opus 5.5 5 of 5. Their median waits were close, 4.5 s against 4.3 s. Claude Opus 5.5 cost 2.0× less, $0.0924 against $0.0459 for the 5 replies. Claude Opus 5.5's replies ran 14% longer, in tokens of reply, thinking not counted.
RAG and answering from documents: Claude Fable 5.1 passed 5 of 5 and Claude Opus 5.5 5 of 5. Claude Opus 5.5 answered 1.4× sooner at the median, 4.0 s against 2.9 s. Claude Opus 5.5 cost 2.0× less, $0.0727 against $0.0367 for the 5 replies. Claude Opus 5.5's replies ran 11% longer, in tokens of reply, thinking not counted.
Math: Claude Fable 5.1 passed 5 of 5 and Claude Opus 5.5 5 of 5. Claude Opus 5.5 answered 1.2× sooner at the median, 4.6 s against 3.9 s. Claude Opus 5.5 cost 2.0× less, $0.0582 against $0.0298 for the 5 replies. Their replies ran to about the same length.
Translation: Claude Fable 5.1 passed 5 of 5 and Claude Opus 5.5 5 of 5. Their median waits were close, 5.1 s against 5.5 s. Claude Opus 5.5 cost 1.6× less, $0.0877 against $0.0540 for the 5 replies. Claude Opus 5.5's replies ran 11% 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 | Claude Opus 5.5, 1.8×took 5.5 s and 3.1 s | Claude Opus 5.5, 3.0×cost $0.0167 and $0.0055 |
| Parse a duration like “1h 30m” | Both passed | Claude Fable 5.1, 1.5×took 4.7 s and 7.2 s | Claude Opus 5.5, 1.5×cost $0.0173 and $0.0112 |
| Merge overlapping intervals | Both passed | Claude Opus 5.5, 1.4×took 5.3 s and 3.7 s | Claude Opus 5.5, 2.8×cost $0.0214 and $0.0077 |
| Evaluate an arithmetic expression, no eval | Both passed | Closetook 15.7 s and 15.8 s | Claude Opus 5.5, 2.6×cost $0.0874 and $0.0336 |
| Parse CSV with quoted fields | Both passed | Claude Opus 5.5, 1.2×took 14.3 s and 11.9 s | Claude Opus 5.5, 2.6×cost $0.0697 and $0.0273 |
| Announce a second bakery shop on LinkedIn | Both passed | Claude Fable 5.1, 1.2×took 7.3 s and 8.7 s | Closecost $0.0184 and $0.0175 |
| Rewrite corporate jargon in plain words | Both passed | Claude Opus 5.5, 1.2×took 6.0 s and 5.1 s | Claude Opus 5.5, 1.7×cost $0.0130 and $0.0078 |
| Decline a meeting and offer two times | Both passed | Claude Opus 5.5, 1.2×took 4.7 s and 4.1 s | Claude Opus 5.5, 2.6×cost $0.0145 and $0.0056 |
| A product announcement with five rules | Only Claude Opus 5.5 | Claude Fable 5.1, 1.4×took 5.9 s and 8.2 s | Closecost $0.0157 and $0.0170 |
| Argue both sides of free buses | Neither passed | Claude Fable 5.1, 2.4×took 9.3 s and 22.5 s | Claude Fable 5.1, 1.8×cost $0.0246 and $0.0443 |
| A discount, then sales tax | Both passed | Claude Opus 5.5, 1.3×took 3.6 s and 2.7 s | Claude Opus 5.5, 2.3×cost $0.0086 and $0.0037 |
| Pens at 3 for $4 | Both passed | Closetook 5.4 s and 5.3 s | Claude Opus 5.5, 1.9×cost $0.0159 and $0.0084 |
| Compound interest over three years | Both passed | Closetook 3.6 s and 3.7 s | Claude Opus 5.5, 2.1×cost $0.0092 and $0.0043 |
| Four-digit numbers whose digits sum to 9 | Both passed | Closetook 4.6 s and 4.7 s | Claude Opus 5.5, 1.8×cost $0.0139 and $0.0077 |
| The highest of three dice is a 5 | Both passed | Claude Opus 5.5, 1.5×took 5.9 s and 3.9 s | Claude Opus 5.5, 1.9×cost $0.0106 and $0.0057 |
| An article in three bullets | Only Claude Opus 5.5 | Claude Fable 5.1, 1.6×took 5.1 s and 8.1 s | Closecost $0.0164 and $0.0171 |
| An email thread in one sentence | Only Claude Opus 5.5 | Closetook 2.5 s and 2.6 s | Claude Opus 5.5, 2.6×cost $0.0114 and $0.0044 |
| Decisions and action items from a meeting | Both passed | Closetook 5.6 s and 5.8 s | Claude Opus 5.5, 1.5×cost $0.0182 and $0.0118 |
| A quarterly memo for the CEO | Both passed | Claude Opus 5.5, 1.4×took 5.0 s and 3.5 s | Claude Opus 5.5, 2.4×cost $0.0184 and $0.0075 |
| A study with a negative result | Both passed | Claude Opus 5.5, 1.3×took 4.9 s and 3.7 s | Claude Opus 5.5, 2.4×cost $0.0160 and $0.0066 |
| The region with the most revenue | Both passed | Closetook 4.1 s and 4.1 s | Claude Opus 5.5, 1.8×cost $0.0159 and $0.0087 |
| Average order value in August | Both passed | Claude Fable 5.1, 1.3×took 3.3 s and 4.4 s | Claude Opus 5.5, 2.0×cost $0.0209 and $0.0107 |
| Revenue change from July to August | Both passed | Closetook 4.9 s and 5.1 s | Claude Opus 5.5, 1.9×cost $0.0232 and $0.0120 |
| A median, filtered two ways | Both passed | Claude Opus 5.5, 1.5×took 6.7 s and 4.6 s | Claude Opus 5.5, 1.9×cost $0.0151 and $0.0079 |
| Correlation between ad spend and sign-ups | Both passed | Claude Opus 5.5, 1.2×took 14.2 s and 11.5 s | Claude Opus 5.5, 2.5×cost $0.0663 and $0.0261 |
| A late order | Both passed | Claude Fable 5.1, 1.3×took 6.1 s and 7.8 s | Claude Opus 5.5, 1.7×cost $0.0199 and $0.0114 |
| A return inside the window | Both passed | Claude Opus 5.5, 1.1×took 4.9 s and 4.4 s | Claude Opus 5.5, 2.4×cost $0.0178 and $0.0074 |
| A frustrated customer | Both passed | Claude Opus 5.5, 1.1×took 7.0 s and 6.4 s | Claude Opus 5.5, 2.0×cost $0.0223 and $0.0111 |
| A refund request outside the window | Both passed | Claude Fable 5.1, 1.4×took 4.5 s and 6.1 s | Claude Opus 5.5, 1.9×cost $0.0204 and $0.0106 |
| A message with a planted instruction | Only Claude Opus 5.5 | Closetook 7.2 s and 7.9 s | Claude Opus 5.5, 2.2×cost $0.0299 and $0.0136 |
| A delivery message into Spanish | Both passed | Claude Opus 5.5, 1.3×took 4.2 s and 3.2 s | Claude Opus 5.5, 2.5×cost $0.0158 and $0.0064 |
| A product description into French | Both passed | Claude Fable 5.1, 1.1×took 5.1 s and 5.8 s | Claude Opus 5.5, 1.4×cost $0.0158 and $0.0113 |
| A meeting note into German | Both passed | Claude Fable 5.1, 1.2×took 4.7 s and 5.5 s | Claude Opus 5.5, 1.6×cost $0.0152 and $0.0096 |
| Idioms into natural Japanese | Both passed | Claude Opus 5.5, 2.3×took 8.5 s and 3.6 s | Claude Opus 5.5, 3.5×cost $0.0217 and $0.0062 |
| A lease clause into Brazilian Portuguese | Both passed | Claude Fable 5.1, 2.0×took 5.6 s and 11.4 s | Closecost $0.0192 and $0.0204 |
| Customers in one country | Both passed | Claude Opus 5.5, 1.3×took 3.2 s and 2.5 s | Claude Opus 5.5, 2.5×cost $0.0120 and $0.0048 |
| Count orders by status | Both passed | Claude Opus 5.5, 1.4×took 3.5 s and 2.5 s | Claude Opus 5.5, 2.5×cost $0.0122 and $0.0049 |
| Revenue by category | Both passed | Closetook 4.5 s and 4.3 s | Claude Opus 5.5, 2.1×cost $0.0190 and $0.0092 |
| Every customer, even those without orders | Both passed | Closetook 5.2 s and 5.0 s | Claude Opus 5.5, 2.1×cost $0.0199 and $0.0094 |
| Monthly revenue with a running total | Both passed | Claude Fable 5.1, 1.2×took 6.3 s and 7.8 s | Claude Opus 5.5, 1.7×cost $0.0293 and $0.0176 |
| A fact from one section | Both passed | Claude Opus 5.5, 1.4×took 3.5 s and 2.5 s | Claude Opus 5.5, 2.5×cost $0.0134 and $0.0054 |
| Core hours and start times | Both passed | Claude Opus 5.5, 1.4×took 3.7 s and 2.6 s | Claude Opus 5.5, 2.5×cost $0.0135 and $0.0054 |
| Two sections in one answer | Both passed | Claude Opus 5.5, 2.2×took 6.3 s and 2.9 s | Claude Opus 5.5, 2.5×cost $0.0133 and $0.0053 |
| A later amendment changes the answer | Both passed | Closetook 7.1 s and 7.7 s | Claude Opus 5.5, 1.1×cost $0.0165 and $0.0148 |
| A question the handbook doesn't answer | Both passed | Claude Opus 5.5, 1.2×took 4.0 s and 3.4 s | Claude Opus 5.5, 2.8×cost $0.0160 and $0.0057 |
| Pick the tool and work out the date | Both passed | Claude Opus 5.5, 1.2×took 3.3 s and 2.7 s | Claude Opus 5.5, 2.5×cost $0.0102 and $0.0041 |
| Convert a currency | Both passed | Claude Opus 5.5, 1.2×took 3.5 s and 2.8 s | Claude Opus 5.5, 2.5×cost $0.0103 and $0.0041 |
| Book a meeting from a sentence | Both passed | Claude Fable 5.1, 2.8×took 2.5 s and 7.2 s | Claude Opus 5.5, 2.2×cost $0.0131 and $0.0059 |
| Search, but don't book | Both passed | Claude Opus 5.5, 1.6×took 5.0 s and 3.1 s | Claude Opus 5.5, 2.5×cost $0.0116 and $0.0046 |
| Two calls with a unit conversion | Both passed | Claude Opus 5.5, 1.4×took 4.8 s and 3.4 s | Claude Opus 5.5, 2.3×cost $0.0145 and $0.0064 |
Claude Fable 5.1 vs Claude Opus 5.5 in our test runs
Claude Fable 5.1 and Claude Opus 5.5 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 Fable 5.1 | Claude Opus 5.5 |
|---|---|---|
| Coding | 5 of 5 | 5 of 5 |
| Writing | 3 of 5 | 4 of 5 |
| Math | 5 of 5 | 5 of 5 |
| Summarization | 3 of 5 | 5 of 5 |
| Data analysis | 5 of 5 | 5 of 5 |
| Customer support | 4 of 5 | 5 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 | 45 of 50 · 1 message each · $0.0200 a reply | 49 of 50 · 1 message each · $0.0107 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, summarization: both replies to a prompt only one of them passed.
An everyday prompt: “An article in three bullets”, in full.
Claude Fable 5.1
Failed: Graded 4.3 of 5 on average (lowest 4); but 62 words, over the 60 allowed.
- Aldmoor's six-month protected bike lane trial on Market Street ended; council votes in November on making it permanent. - Daily bike trips rose from 900 to 2,300, car traffic fell 14%, rush-hour driver times rose about a minute, and cyclist injuries dropped from nine to two. - Businesses were split (27 gained customers, 19 lost); permanence would cost €1.1 million beyond the €410,000 installation.
727 tokens in, 150 out · 5.1 s · $0.0164 · 1 message on Pro · answered by anthropic/claude-fable-5.1 via Anthropic ·
Claude Opus 5.5
Passed: Graded 5.0 of 5 on average (lowest 5).
- Aldmoor's six-month Market Street protected bike lane trial ended; council votes in November on keeping them. - Daily bike trips rose from 900 to 2,300, car traffic fell 14%, rush-hour drive times rose about a minute, and cyclist injuries dropped from nine to two. - Businesses were split; permanence would cost €1.1 million beyond the €410,000 installation.
727 tokens in, 674 out (539 of them reasoning) · 8.1 s · $0.0171 · 1 message on Pro · answered by anthropic/claude-opus-5.5 via Claude Platform on AWS ·
Claude Fable 5.1 and Claude Opus 5.5 on every plan
Whether the one-time free trial reaches each model, then each paid plan's messages on it.
| Plan | Price | Claude Fable 5.1 | Claude Opus 5.5 |
|---|---|---|---|
| Free | $0 | Not in the trial | Not in the trial |
| Plus | $10 a month | Not on Plus | Up to 31 a month |
| Pro | $20 a month | Up to 31 a month | Up to 62 a month |
| Max | $50 a month | Up to 100 a month | Up to 200 a month |
| Ultra | $100 a month | Up to 225 a month | Up to 450 a month |
| Studio | $200 a month | Up to 500 a month | Up to 1,000 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 Claude Fable 5.1.
Context window
Both take up to 1M tokens of context. 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 Fable 5.1 needs Pro or a higher plan and Claude Opus 5.5 needs a paid plan.
Where messages go
Both are Claude models, served the same way. Sent to Anthropic directly.
Fact by fact
| Fact | Claude Fable 5.1 | Claude Opus 5.5 |
|---|---|---|
| Context window | 1M tokens | 1M tokens |
| Reads images | Yes | Yes |
| PDFs | Whole file | Whole file |
| Reasoning | Yes | Yes |
| API price (October 2026) | $10.00 in / $50.00 out per million tokens | $4.00 in / $20.00 out per million tokens |
| A typical message at API prices (4,000 tokens in, 700 out) | $0.0750 | $0.0300 |
| A $10 top-up adds | 25 messages | 50 messages |
| Where a message goes | Sent to Anthropic directly. | Sent to Anthropic 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 Fable 5.1 through OpenRouter instead. | 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. |
| Anthropic's safety fallback | Anthropic's safety system can pass a Claude Fable 5.1 message to another Claude model. The reply then names the model that answered and says what you were charged for. | 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. |
Claude Fable 5.1 or Claude Opus 5.5?
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 Fable 5.1 vs Claude Opus 5.5 is one pair of models. The pages below cover the whole family.
- Claude Fable 5.1: price, limits and messages on every plan
- Claude Opus 5.5: price, limits and messages on every plan
- Claude playground: try Claude online
- Is Claude Fable 5.1 included in Claude Pro?
- Claude Fable 5.1 vs GPT-6 Astra
- Claude Fable 5.1 vs Kimi K3
- Claude Fable 5.1 vs Grok 4.7
- Claude Opus 5.5 vs Claude Sonnet 5
- Claude Opus 5.5 vs Claude Sonnet 5.5
- Gemini 4 Argon vs Claude Opus 5.5
- Every model-vs-model page
Both are made by the same company, so they're served the same way.
Questions
Is Claude Fable 5.1 or Claude Opus 5.5 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 Claude Fable 5.1. 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 Fable 5.1 and Claude Opus 5.5 for free?
Neither is in the free trial of 5 messages: Claude Fable 5.1 needs Pro or a higher plan and Claude Opus 5.5 needs a paid plan.
Which has the bigger context window, Claude Fable 5.1 or Claude Opus 5.5?
Neither: both take 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 Fable 5.1 and Claude Opus 5.5 in the same chat?
Yes. Pick Claude Fable 5.1 for one message and Claude Opus 5.5 for the next; the second sees the whole chat, including the first one's answer.
Which did better in your test runs, Claude Fable 5.1 or Claude Opus 5.5?
On the same 50 prompts, run on September 27, 2026, Claude Fable 5.1 passed 45 and Claude Opus 5.5 passed 49. 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.