DeepSeek V4 Flash 0731 vs GPT-6 Luna vs Inkling Small

GPT-6 Luna is the better all-round choice, scoring 78/100 against DeepSeek V4 Flash 0731 (69) and Inkling Small (62). It leads on capability and inputs & features. DeepSeek V4 Flash 0731 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%. Capability uses the average of shared benchmarks (GPQA Diamond, FrontierMath Tiers 1–3, OTIS Mock AIME 2024–2025 and SimpleQA Verified), because GPT-6 Luna has no Capabilities Index score yet.

DeepSeek V4 Flash 0731 is cheaper at $0.14 input / $0.28 output per million tokens (median across 48 API providers). GPT-6 Luna costs $0.10 input / $0.50 output per million tokens (official OpenAI API price); Inkling Small costs $0.50 input / $1.20 output per million tokens (median across 11 API providers). At a typical mix of three input tokens to one output token, that is $0.175 per million tokens for DeepSeek V4 Flash 0731 versus $0.20 for GPT-6 Luna (1.1× as much) and $0.675 for Inkling Small (3.9× as much).

Not every model here has a Capabilities Index score, so we compare the average of shared benchmarks (GPQA Diamond, FrontierMath Tiers 1–3, OTIS Mock AIME 2024–2025 and SimpleQA Verified): GPT-6 Luna 77.4%, DeepSeek V4 Flash 0731 69.2% and Inkling Small 61.0%. On individual benchmarks: GPQA Diamond — DeepSeek V4 Flash 0731 91.0%, GPT-6 Luna 90.5%, Inkling Small 88.5%; FrontierMath Tiers 1–3 — GPT-6 Luna 79.0%, DeepSeek V4 Flash 0731 57.5%, Inkling Small 46.3%; OTIS Mock AIME 2024–2025 — GPT-6 Luna 98.9%, DeepSeek V4 Flash 0731 94.4%, Inkling Small 90.0%; SimpleQA Verified — GPT-6 Luna 41.4%, DeepSeek V4 Flash 0731 33.6%, Inkling Small 19.1%.

There are no published SWE-bench Verified results for DeepSeek V4 Flash 0731, GPT-6 Luna and Inkling Small yet, so there is no like-for-like coding score. On overall capability, GPT-6 Luna leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

GPT-6 Luna and Inkling Small have the largest context windows (1,050,000 and 1,048,576 tokens), against 1,000,000 for DeepSeek V4 Flash 0731. Maximum output per response: DeepSeek V4 Flash 0731 up to 384,000, GPT-6 Luna up to 128,000, Inkling Small up to 1,048,576 tokens.

DeepSeek V4 Flash 0731 accepts text; GPT-6 Luna accepts text, images and PDFs; Inkling Small accepts text, images and audio. GPT-6 Luna handles the widest range of inputs.

DeepSeek V4 Flash 0731 and Inkling Small publishes its weights (MIT and Apache-2.0) and can be self-hosted; GPT-6 Luna is proprietary.

GPT-6 Luna is the newest, released Sep 22, 2026. DeepSeek V4 Flash 0731 came out Jul 31, 2026; Inkling Small came out Jul 30, 2026. Knowledge cutoff: DeepSeek V4 Flash 0731 May 2025, GPT-6 Luna May 18, 2026.

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.