Which is cheaper, Claude Opus 5.5 and Inkling Small?

Inkling Small has the lowest input price. Per 1M input tokens: Claude Opus 5.5 from $4.00 and Inkling Small from $0.45.

Which has the larger context window, Claude Opus 5.5 and Inkling Small?

Claude Opus 5.5 has the largest context window: Claude Opus 5.5 1,000,000 tokens and Inkling Small 524,288 tokens.

Which is smarter, Claude Opus 5.5 and Inkling Small?

Claude Opus 5.5 scores highest on the Artificial Analysis Intelligence Index: Claude Opus 5.5 59.1 and Inkling Small 12.9.

Can I switch between Claude Opus 5.5 and Inkling Small without changing my code?

Yes. All of them are served through FastRouter's OpenAI-compatible API, so switching is a change of the model parameter (anthropic/claude-opus-5.5, thinkingmachines/inkling-small).

Claude Opus 5.5 vs Inkling Small

Side-by-side pricing per provider, context window, benchmark scores and speed, all on one OpenAI-compatible API.

Estimate monthly cost for these models

Claude Opus 5.5 Anthropicanthropic/claude-opus-5.5

Inkling Small Thinking Machinesthinkingmachines/inkling-small

Creator

Anthropic

Thinking Machines

Released

Sep 22, 2026

Jul 30, 2026

Context window

524K

Max output

128K

262K

Input / 1MLowest provider price

$4.00

$0.45

Output / 1MLowest provider price

$20.00

$1.20

Providers

IntelligenceArtificial Analysis index

59.1

12.9

Accepts

Text, Image, Files

Text, Image, Audio

Produces

Text

Tool calling

Yes

Structured output

Yes

Reasoning

Yes

Claude Opus 5.5 vs Inkling Small: summary

Claude Opus 5.5 and Inkling Small are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Claude Opus 5.5, from Anthropic, has a 1,000,000-token context window, costs from $4.00/1M input and $20.00/1M output tokens across 4 providers and scores 59.1 on the Artificial Analysis Intelligence Index.

Inkling Small, from Thinking Machines, has a 524,288-token context window, costs $0.45/1M input and $1.20/1M output tokens and scores 12.9 on the Artificial Analysis Intelligence Index.

Inkling Small is the cheapest on input, 8.9× cheaper than the next model, Claude Opus 5.5 has the largest context window and Claude Opus 5.5 scores highest for intelligence.

Switch with one line

client = OpenAI(base_url="https://api.fastrouter.ai/api/v1", api_key="<FASTROUTER_API_KEY>") client.chat.completions.create(model="anthropic/claude-opus-5.5", messages=[...]) # or client.chat.completions.create(model="thinkingmachines/inkling-small", messages=[...])

Full API docs

Frequently asked questions

More comparisons

Benchmark scores sourced from ArtificialAnalysis