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Model vs model

Claude Fable 5.1 vs Claude Sonnet 5

Claude Fable 5.1 and Claude Sonnet 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 Sonnet 5 page. Updated .

Short answer

Claude Sonnet 5 gets four times as many messages: up to 125 messages a month on Pro, against up to 31 messages a month for Claude Fable 5.1. Otherwise, only Claude Fable 5.1 can be passed to another model by its maker's safety system and only Claude Sonnet 5 is in the free trial. In our test runs, Claude Fable 5.1 passed 45 of the 50 prompts both answered and Claude Sonnet 5 46; 5 prompts split them, most on writing (3 to 4).

Claude Fable 5.1 vs Claude Sonnet 5, prompt by prompt

Every prompt Claude Fable 5.1 and Claude Sonnet 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 43, only Claude Fable 5.1 passed 2, only Claude Sonnet 5 passed 3, and neither passed 2. Claude Fable 5.1 answered sooner on 5 of the 50 and Claude Sonnet 5 on 39; the rest were within 10% of each other. The 50 replies cost $1.0018 on Claude Fable 5.1 and $0.2030 on Claude Sonnet 5: 4.9× less on Claude Sonnet 5.

The 5 prompts only one of Claude Fable 5.1 and Claude Sonnet 5 passed

  • Announce a second bakery shop on LinkedIn (writing): Claude Fable 5.1 passed and Claude Sonnet 5 didn't. Claude Fable 5.1: Graded 4.8 of 5 on average (lowest 4). Claude Sonnet 5: Graded 3.5 of 5 on average (lowest 3).

  • A product announcement with five rules (writing): Claude Sonnet 5 passed and Claude Fable 5.1 didn't. Claude Fable 5.1: Graded 3.7 of 5 on average (lowest 3). Claude Sonnet 5: Graded 4.3 of 5 on average (lowest 4).

  • Argue both sides of free buses (writing): Claude Sonnet 5 passed and Claude Fable 5.1 didn't. Claude Fable 5.1: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 99 words, over the 90 allowed. Claude Sonnet 5: Graded 4.0 of 5 on average (lowest 4).

  • Correlation between ad spend and sign-ups (data analysis): Claude Fable 5.1 passed and Claude Sonnet 5 didn't. Claude Fable 5.1: Final answer 0.97: right. Claude Sonnet 5: Final answer 0.99; expected 0.97.

  • A message with a planted instruction (customer support): Claude Sonnet 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 Sonnet 5: Graded 4.0 of 5 on average (lowest 3).

Job by job, the widest gaps first

  • Customer support: Claude Fable 5.1 passed 4 of 5 and Claude Sonnet 5 5 of 5. Claude Sonnet 5 answered 1.7× sooner at the median, 6.1 s against 3.5 s. Claude Sonnet 5 cost 6.1× less, $0.1103 against $0.0182 for the 5 replies. Their replies ran to about the same length.

  • Writing: Claude Fable 5.1 passed 3 of 5 and Claude Sonnet 5 4 of 5. Claude Sonnet 5 answered 1.3× sooner at the median, 6.0 s against 4.5 s. Claude Sonnet 5 cost 5.1× less, $0.0862 against $0.0171 for the 5 replies. Their replies ran to about the same length.

  • Data analysis: Claude Fable 5.1 passed 5 of 5 and Claude Sonnet 5 4 of 5. Their median waits were close, 4.9 s against 5.3 s. Claude Sonnet 5 cost 4.1× less, $0.1415 against $0.0344 for the 5 replies. Claude Fable 5.1's replies ran 23% longer, in tokens of reply, thinking not counted.

  • RAG and answering from documents: Claude Fable 5.1 passed 5 of 5 and Claude Sonnet 5 5 of 5. Claude Sonnet 5 answered 2.2× sooner at the median, 4.0 s against 1.8 s. Claude Sonnet 5 cost 6.7× less, $0.0727 against $0.0109 for the 5 replies. Claude Fable 5.1's replies ran 81% longer, in tokens of reply, thinking not counted.

  • SQL: Claude Fable 5.1 passed 5 of 5 and Claude Sonnet 5 5 of 5. Claude Sonnet 5 answered 2.1× sooner at the median, 4.5 s against 2.2 s. Claude Sonnet 5 cost 6.5× less, $0.0924 against $0.0142 for the 5 replies. Claude Fable 5.1's replies ran 38% longer, in tokens of reply, thinking not counted.

  • Translation: Claude Fable 5.1 passed 5 of 5 and Claude Sonnet 5 5 of 5. Claude Sonnet 5 answered 1.9× sooner at the median, 5.1 s against 2.8 s. Claude Sonnet 5 cost 5.9× less, $0.0877 against $0.0149 for the 5 replies. Claude Fable 5.1's replies ran 14% longer, in tokens of reply, thinking not counted.

  • Summarization: Claude Fable 5.1 passed 3 of 5 and Claude Sonnet 5 3 of 5. Claude Sonnet 5 answered 1.8× sooner at the median, 5.0 s against 2.7 s. Claude Sonnet 5 cost 5.8× less, $0.0805 against $0.0140 for the 5 replies. Their replies ran to about the same length.

  • Agents and tool use: Claude Fable 5.1 passed 5 of 5 and Claude Sonnet 5 5 of 5. Claude Sonnet 5 answered 1.8× sooner at the median, 3.5 s against 2.0 s. Claude Sonnet 5 cost 4.9× less, $0.0598 against $0.0121 for the 5 replies. Claude Fable 5.1's replies ran 13% longer, in tokens of reply, thinking not counted.

  • Coding: Claude Fable 5.1 passed 5 of 5 and Claude Sonnet 5 5 of 5. Claude Sonnet 5 answered 2.1× sooner at the median, 5.5 s against 2.7 s. Claude Sonnet 5 cost 4.2× less, $0.2126 against $0.0508 for the 5 replies. Claude Fable 5.1's replies ran 32% longer, in tokens of reply, thinking not counted.

  • Math: Claude Fable 5.1 passed 5 of 5 and Claude Sonnet 5 5 of 5. Claude Sonnet 5 answered 1.2× sooner at the median, 4.6 s against 3.9 s. Claude Sonnet 5 cost 3.5× less, $0.0582 against $0.0165 for the 5 replies. Their replies ran to about the same length.

All 50 prompts: who passed, who answered sooner, who cost less
Claude Fable 5.1 and Claude Sonnet 5 on each prompt of our test runs
PromptResultSoonerCheaper
Turn a title into a URL slugBoth passedClaude Sonnet 5, 2.4×took 5.5 s and 2.3 sClaude Sonnet 5, 6.9×cost $0.0167 and $0.0024
Parse a duration like “1h 30m”Both passedClaude Sonnet 5, 1.8×took 4.7 s and 2.6 sClaude Sonnet 5, 4.8×cost $0.0173 and $0.0036
Merge overlapping intervalsBoth passedClaude Sonnet 5, 2.0×took 5.3 s and 2.7 sClaude Sonnet 5, 6.3×cost $0.0214 and $0.0034
Evaluate an arithmetic expression, no evalBoth passedClosetook 15.7 s and 16.9 sClaude Sonnet 5, 3.9×cost $0.0874 and $0.0226
Parse CSV with quoted fieldsBoth passedClaude Fable 5.1, 1.1×took 14.3 s and 15.8 sClaude Sonnet 5, 3.7×cost $0.0697 and $0.0187
Announce a second bakery shop on LinkedInOnly Claude Fable 5.1Claude Sonnet 5, 1.6×took 7.3 s and 4.6 sClaude Sonnet 5, 4.9×cost $0.0184 and $0.0037
Rewrite corporate jargon in plain wordsBoth passedClaude Sonnet 5, 2.2×took 6.0 s and 2.7 sClaude Sonnet 5, 5.8×cost $0.0130 and $0.0022
Decline a meeting and offer two timesBoth passedClaude Sonnet 5, 1.7×took 4.7 s and 2.8 sClaude Sonnet 5, 5.6×cost $0.0145 and $0.0026
A product announcement with five rulesOnly Claude Sonnet 5Claude Sonnet 5, 1.3×took 5.9 s and 4.5 sClaude Sonnet 5, 4.5×cost $0.0157 and $0.0035
Argue both sides of free busesOnly Claude Sonnet 5Claude Sonnet 5, 1.4×took 9.3 s and 6.6 sClaude Sonnet 5, 4.9×cost $0.0246 and $0.0050
A discount, then sales taxBoth passedClaude Sonnet 5, 1.9×took 3.6 s and 1.9 sClaude Sonnet 5, 5.6×cost $0.0086 and $0.0015
Pens at 3 for $4Both passedClaude Fable 5.1, 1.2×took 5.4 s and 6.3 sClaude Sonnet 5, 2.6×cost $0.0159 and $0.0061
Compound interest over three yearsBoth passedClosetook 3.6 s and 3.7 sClaude Sonnet 5, 4.4×cost $0.0092 and $0.0021
Four-digit numbers whose digits sum to 9Both passedClosetook 4.6 s and 4.5 sClaude Sonnet 5, 3.5×cost $0.0139 and $0.0039
The highest of three dice is a 5Both passedClaude Sonnet 5, 1.5×took 5.9 s and 3.9 sClaude Sonnet 5, 3.8×cost $0.0106 and $0.0028
An article in three bulletsNeither passedClaude Sonnet 5, 1.9×took 5.1 s and 2.6 sClaude Sonnet 5, 6.1×cost $0.0164 and $0.0027
An email thread in one sentenceNeither passedClosetook 2.5 s and 2.3 sClaude Sonnet 5, 5.9×cost $0.0114 and $0.0019
Decisions and action items from a meetingBoth passedClaude Sonnet 5, 2.0×took 5.6 s and 2.8 sClaude Sonnet 5, 5.5×cost $0.0182 and $0.0033
A quarterly memo for the CEOBoth passedClaude Sonnet 5, 1.7×took 5.0 s and 3.0 sClaude Sonnet 5, 5.7×cost $0.0184 and $0.0033
A study with a negative resultBoth passedClaude Sonnet 5, 1.8×took 4.9 s and 2.7 sClaude Sonnet 5, 5.7×cost $0.0160 and $0.0028
The region with the most revenueBoth passedClaude Fable 5.1, 1.6×took 4.1 s and 6.4 sClaude Sonnet 5, 3.9×cost $0.0159 and $0.0041
Average order value in AugustBoth passedClaude Fable 5.1, 1.2×took 3.3 s and 3.9 sClaude Sonnet 5, 5.1×cost $0.0209 and $0.0041
Revenue change from July to AugustBoth passedClosetook 4.9 s and 5.3 sClaude Sonnet 5, 3.7×cost $0.0232 and $0.0062
A median, filtered two waysBoth passedClaude Sonnet 5, 1.4×took 6.7 s and 4.9 sClaude Sonnet 5, 4.2×cost $0.0151 and $0.0036
Correlation between ad spend and sign-upsOnly Claude Fable 5.1Closetook 14.2 s and 13.8 sClaude Sonnet 5, 4.0×cost $0.0663 and $0.0165
A late orderBoth passedClaude Sonnet 5, 1.7×took 6.1 s and 3.5 sClaude Sonnet 5, 5.6×cost $0.0199 and $0.0036
A return inside the windowBoth passedClaude Sonnet 5, 1.7×took 4.9 s and 2.9 sClaude Sonnet 5, 5.5×cost $0.0178 and $0.0032
A frustrated customerBoth passedClaude Sonnet 5, 1.6×took 7.0 s and 4.4 sClaude Sonnet 5, 5.4×cost $0.0223 and $0.0041
A refund request outside the windowBoth passedClaude Sonnet 5, 1.4×took 4.5 s and 3.2 sClaude Sonnet 5, 6.5×cost $0.0204 and $0.0031
A message with a planted instructionOnly Claude Sonnet 5Claude Sonnet 5, 1.6×took 7.2 s and 4.6 sClaude Sonnet 5, 7.3×cost $0.0299 and $0.0041
A delivery message into SpanishBoth passedClaude Sonnet 5, 1.6×took 4.2 s and 2.7 sClaude Sonnet 5, 5.4×cost $0.0158 and $0.0029
A product description into FrenchBoth passedClaude Sonnet 5, 2.0×took 5.1 s and 2.5 sClaude Sonnet 5, 5.5×cost $0.0158 and $0.0029
A meeting note into GermanBoth passedClaude Sonnet 5, 1.7×took 4.7 s and 2.8 sClaude Sonnet 5, 5.7×cost $0.0152 and $0.0027
Idioms into natural JapaneseBoth passedClaude Sonnet 5, 2.1×took 8.5 s and 4.1 sClaude Sonnet 5, 7.8×cost $0.0217 and $0.0028
A lease clause into Brazilian PortugueseBoth passedClaude Sonnet 5, 1.5×took 5.6 s and 3.8 sClaude Sonnet 5, 5.4×cost $0.0192 and $0.0036
Customers in one countryBoth passedClaude Sonnet 5, 1.7×took 3.2 s and 1.8 sClaude Sonnet 5, 5.9×cost $0.0120 and $0.0020
Count orders by statusBoth passedClaude Sonnet 5, 1.8×took 3.5 s and 2.0 sClaude Sonnet 5, 6.2×cost $0.0122 and $0.0020
Revenue by categoryBoth passedClaude Sonnet 5, 1.3×took 4.5 s and 3.5 sClaude Sonnet 5, 6.2×cost $0.0190 and $0.0031
Every customer, even those without ordersBoth passedClaude Sonnet 5, 2.4×took 5.2 s and 2.2 sClaude Sonnet 5, 6.6×cost $0.0199 and $0.0030
Monthly revenue with a running totalBoth passedClaude Sonnet 5, 2.1×took 6.3 s and 3.0 sClaude Sonnet 5, 7.0×cost $0.0293 and $0.0042
A fact from one sectionBoth passedClaude Sonnet 5, 2.1×took 3.5 s and 1.7 sClaude Sonnet 5, 6.9×cost $0.0134 and $0.0019
Core hours and start timesBoth passedClaude Sonnet 5, 1.8×took 3.7 s and 2.1 sClaude Sonnet 5, 6.2×cost $0.0135 and $0.0022
Two sections in one answerBoth passedClaude Sonnet 5, 3.4×took 6.3 s and 1.8 sClaude Sonnet 5, 6.0×cost $0.0133 and $0.0022
A later amendment changes the answerBoth passedClaude Sonnet 5, 3.4×took 7.1 s and 2.1 sClaude Sonnet 5, 6.3×cost $0.0165 and $0.0026
A question the handbook doesn't answerBoth passedClaude Sonnet 5, 2.2×took 4.0 s and 1.8 sClaude Sonnet 5, 8.4×cost $0.0160 and $0.0019
Pick the tool and work out the dateBoth passedClaude Sonnet 5, 1.9×took 3.3 s and 1.7 sClaude Sonnet 5, 5.8×cost $0.0102 and $0.0018
Convert a currencyBoth passedClaude Sonnet 5, 1.8×took 3.5 s and 2.0 sClaude Sonnet 5, 5.8×cost $0.0103 and $0.0018
Book a meeting from a sentenceBoth passedClaude Fable 5.1, 2.2×took 2.5 s and 5.7 sClaude Sonnet 5, 3.5×cost $0.0131 and $0.0037
Search, but don't bookBoth passedClaude Sonnet 5, 2.7×took 5.0 s and 1.9 sClaude Sonnet 5, 5.8×cost $0.0116 and $0.0020
Two calls with a unit conversionBoth passedClaude Sonnet 5, 1.3×took 4.8 s and 3.8 sClaude Sonnet 5, 5.1×cost $0.0145 and $0.0028

Claude Fable 5.1 vs Claude Sonnet 5 in our test runs

Claude Fable 5.1 and Claude Sonnet 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 .

Claude Fable 5.1 and Claude Sonnet 5 in our test runs, job by job
JobClaude Fable 5.1Claude Sonnet 5
Coding5 of 55 of 5
Writing3 of 54 of 5
Math5 of 55 of 5
Summarization3 of 53 of 5
Data analysis5 of 54 of 5
Customer support4 of 55 of 5
Translation5 of 55 of 5
SQL5 of 55 of 5
RAG and answering from documents5 of 55 of 5
Agents and tool use5 of 55 of 5
All jobs45 of 50 · 1 message each · $0.0200 a reply46 of 50 · 1 message each · $0.0041 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, writing: both replies to a prompt only one of them passed.

An everyday prompt: “Announce a second bakery shop on LinkedIn”, in full.

  • Claude Fable 5.1

    Passed: Graded 4.8 of 5 on average (lowest 4).

    We're opening a second Crumb & Co.
    
    When we started baking out of one small shop, we didn't imagine we'd ever need a second oven, let alone a second door. But our customers kept coming back, kept telling their friends, and kept asking whether we might ever open somewhere closer to them. So we listened.
    
    On 14 November, Crumb & Co. opens in Leeds.
    
    It'll be the same bread, the same pastries, and the same early mornings, just in a new neighbourhood. We've been baking test batches for weeks to make sure the first loaf out of the Leeds oven tastes exactly like the ones you already know.
    
    To say thank you, coffee is on us all day on opening day. Come by, have a cup, and try something warm from the counter.
    
    We'd love to see you there. Thank you for getting us here.

    540 tokens in, 259 out · 7.3 s · $0.0184 · 1 message on Pro · answered by anthropic/claude-fable-5.1 via Anthropic ·

  • Claude Sonnet 5

    Failed: Graded 3.5 of 5 on average (lowest 3).

    We have some exciting news to share: Crumb & Co. is opening our second shop, this time in Leeds!
    
    From our very first bakery, we've believed in doing simple things well — proper sourdough, honest pastries, and coffee worth stopping for. Now we get to bring that same spirit to a new neighbourhood and, hopefully, a whole new group of familiar faces.
    
    Our Leeds shop opens its doors on 14 November, and we'd love for you to be there. To celebrate, every coffee on opening day is on us — no catch, just our way of saying thank you for supporting us along the way.
    
    This has been months of planning, a lot of taste-testing, and more excitement than we know what to do with. We can't wait to welcome you in, share some fresh bakes, and start building new memories together.
    
    See you there — first coffee's on the house.

    538 tokens in, 267 out · 4.6 s · $0.0037 · 1 message on Pro · answered by anthropic/claude-sonnet-5 via Claude Platform on AWS ·

Claude Fable 5.1 and Claude Sonnet 5 on every plan

Whether the one-time free trial reaches each model, then each paid plan's messages on it.

Messages on Claude Fable 5.1 and Claude Sonnet 5, plan by plan
PlanPriceClaude Fable 5.1Claude Sonnet 5
Free$0Not in the trialIn the one-time trial of 5 messages
Pro$20 a monthUp to 31 a monthUp to 125 a month
Max$50 a monthUp to 100 a monthUp to 400 a month
Ultra$100 a monthUp to 225 a monthUp to 900 a month
Studio$200 a monthUp to 500 a monthUp to 2,000 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: 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 Sonnet 5 gets four times as many messages: up to 125 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

    Claude Sonnet 5 is in the free trial; Claude Fable 5.1 needs a paid plan.

  • Where messages go

    Both are Claude models, served the same way. Sent to Anthropic directly.

Fact by fact

Claude Fable 5.1 and Claude Sonnet 5, fact by fact
FactClaude Fable 5.1Claude Sonnet 5
Context window1M tokens1M tokens
Reads imagesYesYes
PDFsWhole fileWhole file
ReasoningYesYes
API price (September 2026)$10.00 in / $50.00 out per million tokens$2.00 in / $10.00 out per million tokens
A typical message at API prices (4,000 tokens in, 700 out)$0.0750$0.0150
A $10 top-up adds25 messages100 messages
Where a message goesSent to Anthropic directly.Sent to Anthropic directly.
If the provider failsIf 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 Sonnet 5 through OpenRouter instead.
Anthropic's safety fallbackAnthropic'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.Doesn't apply
API prices are what our model catalog lists (Claude: Anthropic's list price). In llmwise you pay per message, not per token: the counts above are what you get.

Claude Fable 5.1 or Claude Sonnet 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 Sonnet 5: more messages for the money, up to 125 messages a month on Pro; you can try it in the free trial.

Each model's page, the families, and other pairs

Claude Fable 5.1 vs Claude Sonnet 5 is one pair of models. The pages below cover the whole family.

Questions

Is Claude Fable 5.1 or Claude Sonnet 5 cheaper in llmwise?

Claude Sonnet 5 gets four times as many messages: up to 125 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 all models, so each count is the most you get if it all goes to that model.

Can I try Claude Fable 5.1 and Claude Sonnet 5 for free?

Claude Sonnet 5 is, in the free trial of 5 messages; Claude Fable 5.1 needs a paid plan.

Which has the bigger context window, Claude Fable 5.1 or Claude Sonnet 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 Sonnet 5 in the same chat?

Yes. Pick Claude Fable 5.1 for one message and Claude Sonnet 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 Sonnet 5?

On the same 50 prompts, run on September 27, 2026, Claude Fable 5.1 passed 45 and Claude Sonnet 5 passed 46. The table on this page has each job, and every reply is published.

Claude, GPT, Gemini, DeepSeek, Grok, Kimi, and GLM, 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.