Head-to-head comparison
DeepSeek V3.1 Terminus (DeepSeek) and Inkling Small (Thinking Machines) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.
Snapshot as of 9 September 2026
As of 9 September 2026, DeepSeek V3.1 Terminus holds the stronger ModelCap Index position (#62 vs #64); DeepSeek V3.1 Terminus is 1.2× cheaper per output token ($1.00/1M vs $1.20/1M); and Inkling Small offers the longer context window (1M vs 164K tokens).
Evidence: 3 public benchmark observations across 3 boards · 5 public benchmark observations across 5 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.
Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.
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DeepSeek V3.1 Terminus ranks higher on the ModelCap Index as of 9 September 2026: #62 against #64. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it. Their published uncertainty intervals overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.
DeepSeek V3.1 Terminus is cheaper on output tokens: $1.00/1M against $1.20/1M. Input tokens are $0.27/1M for DeepSeek V3.1 Terminus and $0.45/1M for Inkling Small. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $1.04 for DeepSeek V3.1 Terminus versus $1.50 for Inkling Small. DeepSeek V3.1 Terminus costs 30.7% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.
Inkling Small has the larger context window: 1M tokens against 164K.
Arena coding: DeepSeek V3.1 Terminus 1461, Inkling Small 1477 — Inkling Small leads. AA Terminal-Bench 2.1: DeepSeek V3.1 Terminus 44.9%, Inkling Small 55.1% — Inkling Small leads.
DeepSeek V3.1 Terminus: Open weights. Inkling Small: Open weights. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.
ModelCap currently lists 4 API providers for DeepSeek V3.1 Terminus and 3 for Inkling Small, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.
Every figure comes from the sealed ModelCap dataset published 9 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.