Model vs model
Claude Sonnet 5.5 vs Kimi K3
Claude Sonnet 5.5 and Kimi K3 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 Sonnet 5.5 page, OpenRouter's Kimi K3 page. Updated .
Short answer
They cost the same in llmwise: up to 125 messages a month on Pro on either. Otherwise, only Claude Sonnet 5.5 reads a PDF as the whole file and only Claude Sonnet 5.5 can be passed to another model by its maker's safety system. In our test runs, Claude Sonnet 5.5 passed 47 of the 50 prompts both answered and Kimi K3 46; 5 prompts split them, most on summarization (4 to 3).
Claude Sonnet 5.5 vs Kimi K3, prompt by prompt
Every prompt Claude Sonnet 5.5 and Kimi K3 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 44, only Claude Sonnet 5.5 passed 3, only Kimi K3 passed 2, and neither passed 1. Claude Sonnet 5.5 answered sooner on 38 of the 50 and Kimi K3 on 6; the rest were within 10% of each other. The 50 replies cost $0.1912 on Claude Sonnet 5.5 and $0.1938 on Kimi K3: about the same for both.
The 5 prompts only one of Claude Sonnet 5.5 and Kimi K3 passed
A product announcement with five rules (writing): Claude Sonnet 5.5 passed and Kimi K3 didn't. Claude Sonnet 5.5: Graded 4.3 of 5 on average (lowest 4). Kimi K3: Graded 4.3 of 5 on average (lowest 4); but doesn't end with a question.
Argue both sides of free buses (writing): Kimi K3 passed and Claude Sonnet 5.5 didn't. Claude Sonnet 5.5: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 98 words, over the 90 allowed. Kimi K3: Graded 4.7 of 5 on average (lowest 4).
An article in three bullets (summarization): Claude Sonnet 5.5 passed and Kimi K3 didn't. Claude Sonnet 5.5: Graded 4.7 of 5 on average (lowest 4). Kimi K3: Graded 4.0 of 5 on average (lowest 3); but 62 words, over the 60 allowed.
A frustrated customer (customer support): Kimi K3 passed and Claude Sonnet 5.5 didn't. Claude Sonnet 5.5: Graded 3.7 of 5 on average (lowest 2). Kimi K3: Graded 4.0 of 5 on average (lowest 3).
A refund request outside the window (customer support): Claude Sonnet 5.5 passed and Kimi K3 didn't. Claude Sonnet 5.5: Graded 4.7 of 5 on average (lowest 4). Kimi K3: Graded 4.0 of 5 on average (lowest 2).
Job by job, the widest gaps first
Summarization: Claude Sonnet 5.5 passed 4 of 5 and Kimi K3 3 of 5. Claude Sonnet 5.5 answered 1.7× sooner at the median, 1.9 s against 3.4 s. They cost about the same, $0.0168 against $0.0172 for the 5 replies. Claude Sonnet 5.5's replies ran 52% longer, in tokens of reply, thinking not counted.
RAG and answering from documents: Claude Sonnet 5.5 passed 5 of 5 and Kimi K3 5 of 5. Claude Sonnet 5.5 answered 2.0× sooner at the median, 1.4 s against 2.6 s. Kimi K3 cost 1.9× less, $0.0140 against $0.0073 for the 5 replies. Claude Sonnet 5.5's replies ran 40% longer, in tokens of reply, thinking not counted.
SQL: Claude Sonnet 5.5 passed 5 of 5 and Kimi K3 5 of 5. Kimi K3 answered 1.1× sooner at the median, 1.8 s against 1.6 s. Kimi K3 cost 1.6× less, $0.0190 against $0.0118 for the 5 replies. Claude Sonnet 5.5's replies ran 114% longer, in tokens of reply, thinking not counted.
Math: Claude Sonnet 5.5 passed 5 of 5 and Kimi K3 5 of 5. Claude Sonnet 5.5 answered 3.2× sooner at the median, 1.7 s against 5.4 s. Claude Sonnet 5.5 cost 1.5× less, $0.0123 against $0.0187 for the 5 replies. Claude Sonnet 5.5's replies ran 78% longer, in tokens of reply, thinking not counted.
Data analysis: Claude Sonnet 5.5 passed 5 of 5 and Kimi K3 5 of 5. Claude Sonnet 5.5 answered 1.5× sooner at the median, 2.3 s against 3.5 s. Claude Sonnet 5.5 cost 1.4× less, $0.0235 against $0.0339 for the 5 replies. Claude Sonnet 5.5's replies ran 67% longer, in tokens of reply, thinking not counted.
Translation: Claude Sonnet 5.5 passed 5 of 5 and Kimi K3 5 of 5. Claude Sonnet 5.5 answered 2.3× sooner at the median, 2.3 s against 5.2 s. Kimi K3 cost 1.2× less, $0.0211 against $0.0179 for the 5 replies. Claude Sonnet 5.5's replies ran 30% longer, in tokens of reply, thinking not counted.
Writing: Claude Sonnet 5.5 passed 4 of 5 and Kimi K3 4 of 5. Claude Sonnet 5.5 answered 1.3× sooner at the median, 2.3 s against 3.0 s. Claude Sonnet 5.5 cost 1.1× less, $0.0171 against $0.0192 for the 5 replies. Claude Sonnet 5.5's replies ran 51% longer, in tokens of reply, thinking not counted.
Agents and tool use: Claude Sonnet 5.5 passed 5 of 5 and Kimi K3 5 of 5. Claude Sonnet 5.5 answered 1.4× sooner at the median, 1.4 s against 2.0 s. They cost about the same, $0.0129 against $0.0135 for the 5 replies. Claude Sonnet 5.5's replies ran 20% longer, in tokens of reply, thinking not counted.
Customer support: Claude Sonnet 5.5 passed 4 of 5 and Kimi K3 4 of 5. Claude Sonnet 5.5 answered 1.7× sooner at the median, 2.5 s against 4.3 s. They cost about the same, $0.0232 against $0.0228 for the 5 replies. Claude Sonnet 5.5's replies ran 39% longer, in tokens of reply, thinking not counted.
Coding: Claude Sonnet 5.5 passed 5 of 5 and Kimi K3 5 of 5. Claude Sonnet 5.5 answered 2.1× sooner at the median, 2.0 s against 4.1 s. They cost about the same, $0.0313 against $0.0316 for the 5 replies. Claude Sonnet 5.5's replies ran 50% 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 Sonnet 5.5, 1.4×took 1.8 s and 2.6 s | Claude Sonnet 5.5, 1.3×cost $0.0028 and $0.0035 |
| Parse a duration like “1h 30m” | Both passed | Claude Sonnet 5.5, 3.6×took 2.0 s and 7.1 s | Claude Sonnet 5.5, 1.7×cost $0.0036 and $0.0063 |
| Merge overlapping intervals | Both passed | Claude Sonnet 5.5, 1.5×took 1.4 s and 2.0 s | Closecost $0.0033 and $0.0036 |
| Evaluate an arithmetic expression, no eval | Both passed | Claude Sonnet 5.5, 2.1×took 4.8 s and 9.9 s | Claude Sonnet 5.5, 1.1×cost $0.0102 and $0.0113 |
| Parse CSV with quoted fields | Both passed | Kimi K3, 1.3×took 5.3 s and 4.1 s | Kimi K3, 1.7×cost $0.0114 and $0.0069 |
| Announce a second bakery shop on LinkedIn | Both passed | Claude Sonnet 5.5, 1.2×took 3.3 s and 3.9 s | Claude Sonnet 5.5, 1.3×cost $0.0035 and $0.0046 |
| Rewrite corporate jargon in plain words | Both passed | Claude Sonnet 5.5, 1.2×took 1.6 s and 2.0 s | Claude Sonnet 5.5, 1.2×cost $0.0025 and $0.0030 |
| Decline a meeting and offer two times | Both passed | Claude Sonnet 5.5, 1.3×took 2.3 s and 3.0 s | Claude Sonnet 5.5, 1.1×cost $0.0030 and $0.0034 |
| A product announcement with five rules | Only Claude Sonnet 5.5 | Closetook 2.3 s and 2.3 s | Claude Sonnet 5.5, 1.1×cost $0.0030 and $0.0033 |
| Argue both sides of free buses | Only Kimi K3 | Kimi K3, 1.2×took 4.4 s and 3.6 s | Closecost $0.0051 and $0.0049 |
| A discount, then sales tax | Both passed | Claude Sonnet 5.5, 3.1×took 1.6 s and 5.0 s | Claude Sonnet 5.5, 2.1×cost $0.0017 and $0.0037 |
| Pens at 3 for $4 | Both passed | Claude Sonnet 5.5, 2.5×took 2.2 s and 5.4 s | Claude Sonnet 5.5, 1.3×cost $0.0036 and $0.0046 |
| Compound interest over three years | Both passed | Claude Sonnet 5.5, 4.7×took 1.3 s and 5.9 s | Claude Sonnet 5.5, 2.1×cost $0.0021 and $0.0044 |
| Four-digit numbers whose digits sum to 9 | Both passed | Claude Sonnet 5.5, 3.4×took 1.8 s and 6.0 s | Claude Sonnet 5.5, 1.2×cost $0.0026 and $0.0032 |
| The highest of three dice is a 5 | Both passed | Claude Sonnet 5.5, 1.5×took 1.7 s and 2.4 s | Claude Sonnet 5.5, 1.2×cost $0.0022 and $0.0027 |
| An article in three bullets | Only Claude Sonnet 5.5 | Claude Sonnet 5.5, 1.4×took 1.9 s and 2.8 s | Kimi K3, 1.1×cost $0.0031 and $0.0028 |
| An email thread in one sentence | Neither passed | Claude Sonnet 5.5, 4.4×took 1.4 s and 6.4 s | Claude Sonnet 5.5, 1.3×cost $0.0023 and $0.0030 |
| Decisions and action items from a meeting | Both passed | Claude Sonnet 5.5, 1.6×took 2.2 s and 3.4 s | Closecost $0.0043 and $0.0044 |
| A quarterly memo for the CEO | Both passed | Claude Sonnet 5.5, 8.5×took 1.8 s and 15.7 s | Claude Sonnet 5.5, 1.3×cost $0.0037 and $0.0049 |
| A study with a negative result | Both passed | Claude Sonnet 5.5, 1.4×took 2.4 s and 3.2 s | Kimi K3, 1.6×cost $0.0034 and $0.0021 |
| The region with the most revenue | Both passed | Closetook 2.4 s and 2.2 s | Closecost $0.0051 and $0.0049 |
| Average order value in August | Both passed | Claude Sonnet 5.5, 1.5×took 1.7 s and 2.7 s | Claude Sonnet 5.5, 1.4×cost $0.0037 and $0.0054 |
| Revenue change from July to August | Both passed | Claude Sonnet 5.5, 2.8×took 2.3 s and 6.4 s | Claude Sonnet 5.5, 1.3×cost $0.0048 and $0.0064 |
| A median, filtered two ways | Both passed | Claude Sonnet 5.5, 2.3×took 1.5 s and 3.5 s | Claude Sonnet 5.5, 1.4×cost $0.0030 and $0.0042 |
| Correlation between ad spend and sign-ups | Both passed | Claude Sonnet 5.5, 4.8×took 4.2 s and 20.2 s | Claude Sonnet 5.5, 1.9×cost $0.0070 and $0.0131 |
| A late order | Both passed | Closetook 2.5 s and 2.5 s | Claude Sonnet 5.5, 1.2×cost $0.0038 and $0.0045 |
| A return inside the window | Both passed | Claude Sonnet 5.5, 2.0×took 2.2 s and 4.3 s | Closecost $0.0035 and $0.0033 |
| A frustrated customer | Only Kimi K3 | Claude Sonnet 5.5, 2.1×took 2.7 s and 5.6 s | Claude Sonnet 5.5, 1.5×cost $0.0042 and $0.0063 |
| A refund request outside the window | Only Claude Sonnet 5.5 | Claude Sonnet 5.5, 1.3×took 2.0 s and 2.6 s | Claude Sonnet 5.5, 1.2×cost $0.0038 and $0.0045 |
| A message with a planted instruction | Both passed | Claude Sonnet 5.5, 1.9×took 6.1 s and 11.5 s | Kimi K3, 1.9×cost $0.0079 and $0.0041 |
| A delivery message into Spanish | Both passed | Claude Sonnet 5.5, 1.9×took 1.5 s and 2.9 s | Closecost $0.0032 and $0.0031 |
| A product description into French | Both passed | Claude Sonnet 5.5, 3.0×took 1.8 s and 5.4 s | Claude Sonnet 5.5, 1.2×cost $0.0032 and $0.0037 |
| A meeting note into German | Both passed | Claude Sonnet 5.5, 1.3×took 2.3 s and 3.0 s | Kimi K3, 2.8×cost $0.0038 and $0.0014 |
| Idioms into natural Japanese | Both passed | Claude Sonnet 5.5, 1.8×took 2.9 s and 5.2 s | Claude Sonnet 5.5, 1.1×cost $0.0046 and $0.0053 |
| A lease clause into Brazilian Portuguese | Both passed | Claude Sonnet 5.5, 2.3×took 4.4 s and 10.1 s | Kimi K3, 1.4×cost $0.0063 and $0.0044 |
| Customers in one country | Both passed | Kimi K3, 1.6×took 1.8 s and 1.1 s | Kimi K3, 1.4×cost $0.0024 and $0.0018 |
| Count orders by status | Both passed | Claude Sonnet 5.5, 1.6×took 1.0 s and 1.5 s | Kimi K3, 2.9×cost $0.0024 and $0.0009 |
| Revenue by category | Both passed | Closetook 1.6 s and 1.6 s | Kimi K3, 2.1×cost $0.0039 and $0.0019 |
| Every customer, even those without orders | Both passed | Claude Sonnet 5.5, 1.1×took 2.3 s and 2.5 s | Kimi K3, 1.4×cost $0.0043 and $0.0031 |
| Monthly revenue with a running total | Both passed | Closetook 2.7 s and 2.5 s | Kimi K3, 1.4×cost $0.0060 and $0.0042 |
| A fact from one section | Both passed | Claude Sonnet 5.5, 4.8×took 1.4 s and 6.5 s | Kimi K3, 2.7×cost $0.0027 and $0.0010 |
| Core hours and start times | Both passed | Kimi K3, 1.1×took 1.4 s and 1.2 s | Kimi K3, 2.5×cost $0.0027 and $0.0011 |
| Two sections in one answer | Both passed | Claude Sonnet 5.5, 2.0×took 1.3 s and 2.6 s | Kimi K3, 1.4×cost $0.0027 and $0.0020 |
| A later amendment changes the answer | Both passed | Claude Sonnet 5.5, 3.9×took 1.2 s and 4.8 s | Kimi K3, 1.4×cost $0.0031 and $0.0022 |
| A question the handbook doesn't answer | Both passed | Kimi K3, 1.4×took 1.4 s and 0.9 s | Kimi K3, 2.8×cost $0.0028 and $0.0010 |
| Pick the tool and work out the date | Both passed | Claude Sonnet 5.5, 3.0×took 1.3 s and 3.7 s | Claude Sonnet 5.5, 1.5×cost $0.0021 and $0.0032 |
| Convert a currency | Both passed | Claude Sonnet 5.5, 2.9×took 1.0 s and 2.9 s | Claude Sonnet 5.5, 1.2×cost $0.0021 and $0.0025 |
| Book a meeting from a sentence | Both passed | Closetook 1.5 s and 1.6 s | Claude Sonnet 5.5, 1.2×cost $0.0026 and $0.0031 |
| Search, but don't book | Both passed | Claude Sonnet 5.5, 1.4×took 1.4 s and 2.0 s | Claude Sonnet 5.5, 1.5×cost $0.0023 and $0.0034 |
| Two calls with a unit conversion | Both passed | Kimi K3, 2.2×took 3.7 s and 1.7 s | Kimi K3, 3.0×cost $0.0038 and $0.0012 |
Claude Sonnet 5.5 vs Kimi K3 in our test runs
Claude Sonnet 5.5 and Kimi K3 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 Sonnet 5.5 | Kimi K3 |
|---|---|---|
| Coding | 5 of 5 | 5 of 5 |
| Writing | 4 of 5 | 4 of 5 |
| Math | 5 of 5 | 5 of 5 |
| Summarization | 4 of 5 | 3 of 5 |
| Data analysis | 5 of 5 | 5 of 5 |
| Customer support | 4 of 5 | 4 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 | 47 of 50 · 1 message each · $0.0038 a reply | 46 of 50 · 1 message each · $0.0039 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 Sonnet 5.5
Passed: Graded 4.7 of 5 on average (lowest 4).
- Aldmoor's six-month Market Street bike-lane trial raised daily bike trips from about 900 to 2,300, cut car traffic 14%, and added just over a minute to rush-hour drives. - Injuries fell from nine to two; businesses were split, with 27 reporting more customers, 19 fewer. - Council votes in November; permanence would cost another €1.1 million.
729 tokens in, 130 out · 1.9 s · $0.0031 · 1 message on Pro · answered by anthropic/claude-sonnet-5.5 via Anthropic ·
Kimi K3
Failed: Graded 4.0 of 5 on average (lowest 3); but 62 words, over the 60 allowed.
- Aldmoor's six-month protected bike lane trial on Market Street ended; the council votes in November on making them permanent. - Bike trips rose from 900 to 2,300 daily, cyclist injuries dropped from nine to two, while car traffic fell 14% with only slightly longer rush-hour drive times. - Businesses were split on customer impact; installation cost €410,000, with permanent lanes requiring €1.1 million more.
608 tokens in, 109 out (10 of them reasoning) · 2.8 s · $0.0028 · 1 message on Pro · answered by moonshotai/kimi-k3 via Phala ·
Claude Sonnet 5.5 and Kimi K3 on every plan
Whether the one-time free trial reaches each model, then each paid plan's messages on it.
| Plan | Price | Claude Sonnet 5.5 | Kimi K3 |
|---|---|---|---|
| Free | $0 | In the one-time trial of 5 messages | In the one-time trial of 5 messages |
| Pro | $20 a month | Up to 125 a month | Up to 125 a month |
| Max | $50 a month | Up to 400 a month | Up to 400 a month |
| Ultra | $100 a month | Up to 900 a month | Up to 900 a month |
| Studio | $200 a month | Up to 2,000 a month | Up 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
They cost the same in llmwise: up to 125 messages a month on Pro on either.
Context window
Claude Sonnet 5.5 takes up to 1M tokens; Kimi K3 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. Kimi K3 gets a PDF's text rather than the file itself.
On Free
Both are in the free trial.
Where messages go
Claude Sonnet 5.5: Sent to Anthropic directly. Kimi K3: Served through OpenRouter, only by hosts that don't store or train on prompts. The maker's own endpoint is never asked.
Fact by fact
| Fact | Claude Sonnet 5.5 | Kimi K3 |
|---|---|---|
| Context window | 1M tokens | 1.05M tokens |
| Reads images | Yes | Yes |
| PDFs | Whole file | Text only |
| Reasoning | Yes | Yes |
| API price (September 2026) | $2.00 in / $10.00 out per million tokens | $3.00 in / $15.00 out per million tokens |
| A typical message at API prices (4,000 tokens in, 700 out) | $0.0150 | $0.0225 |
| A $10 top-up adds | 100 messages | 100 messages |
| Where a message goes | Sent to Anthropic directly. | Served through OpenRouter, only by hosts that don't store or train on prompts. The maker's own endpoint is never asked. |
| 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 Sonnet 5.5 through OpenRouter instead. | When one host is down, OpenRouter moves the request to another host that meets the same rules. |
| Anthropic's safety fallback | Anthropic's safety system can pass a Claude Sonnet 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 Sonnet 5.5 or Kimi K3?
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 5.5: it reads a PDF as the whole file, charts and scans included; it costs its maker less to run ($0.0150 a typical message at API prices), though in llmwise the count is the same.
Each model's page, the families, and other pairs
Claude Sonnet 5.5 vs Kimi K3 is one pair of models. The page below covers the whole families.
- Claude Sonnet 5.5: price, limits and messages on every plan
- Kimi K3: price, limits and messages on every plan
- Claude vs Kimi
- Claude Sonnet 5.5 vs GPT-6 Sol
- Claude Sonnet 5.5 vs Claude Sonnet 5
- Claude Opus 5.5 vs Claude Sonnet 5.5
- Claude Fable 5.1 vs Kimi K3
- Kimi K3 vs GLM 5.3
- DeepSeek V4 Pro vs Kimi K3
- Every model-vs-model page
Claude Sonnet 5.5 is a Claude model; Kimi K3 is a Kimi model.
Questions
Is Claude Sonnet 5.5 or Kimi K3 cheaper in llmwise?
They cost the same in llmwise: up to 125 messages a month on Pro on either. 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 Sonnet 5.5 and Kimi K3 for free?
Yes: both are in the free trial of 5 messages.
Which has the bigger context window, Claude Sonnet 5.5 or Kimi K3?
Kimi K3: 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 Sonnet 5.5 and Kimi K3 in the same chat?
Yes. Pick Claude Sonnet 5.5 for one message and Kimi K3 for the next; the second sees the whole chat, including the first one's answer.
Which did better in your test runs, Claude Sonnet 5.5 or Kimi K3?
On the same 50 prompts, run on September 28, 2026, Claude Sonnet 5.5 passed 47 and Kimi K3 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.