Skip to content
ModelCap

Head-to-head comparison

GPT-5.6 Luna vs Qwen3.8 Flash

GPT-5.6 Luna (OpenAI) and Qwen3.8 Flash (Qwen) 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 3 September 2026

As of 3 September 2026, Qwen3.8 Flash holds the stronger ModelCap Index position (#17 vs #18); and Qwen3.8 Flash is 2.6× cheaper per output token ($0.47/1M vs $1.20/1M).

Which should you choose?

Choose GPT-5.6 Luna if…

  • you want provider choice — 3 listed API providers against 1.
  • AA Humanity's Last Exam is your yardstick — 39.5% against 38.0%.

Choose Qwen3.8 Flash if…

  • you want the stronger overall ModelCap Index position — #17 against #18 (72.1 vs 69.7 points).
  • API cost matters — $0.47/1M output tokens against $1.20/1M, about 2.6× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.15/1M against $0.20/1M.
  • AA Intelligence Index is your yardstick — 55.8 against 52.3.
  • AA Terminal-Bench 2.1 is your yardstick — 86.1% against 80.9%.
  • you want the more recently listed model — Qwen3.8 Flash was listed 26 August 2026, GPT-5.6 Luna 9 July 2026.

GPT-5.6 Luna vs Qwen3.8 Flash: specs, pricing and context

Specification comparison of GPT-5.6 Luna and Qwen3.8 Flash
FieldGPT-5.6 LunaOpenAIQwen3.8 FlashQwen
ModelCap Index position#18#17
Index score69.772.1
EvidenceMeasuredMeasured
Input price / 1M tokens$0.20$0.15
Output price / 1M tokens$1.20$0.47
Context window1M tokens1M tokens
Max output tokens128K131K
API providers listed31
Weight accessAPI onlyRestricted license
Input modalitiesFile, Image, TextText, Image, Video
First listed9 July 202626 August 2026
PublisherOpenAIQwen

Evidence: 6 public benchmark observations across 6 boards · 1 public benchmark observation across 1 board. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: GPT-5.6 Luna vs Qwen3.8 Flash

Public benchmark boards where GPT-5.6 Luna or Qwen3.8 Flash has a published result
BoardGPT-5.6 LunaQwen3.8 FlashLeads
Arena codingArena (LMArena)14971489–1505X-High—Only one result
LMArena AgentLMArena2.1%0.9%–3.4%X-High—Only one result
ARC-AGI-2ARC Prize Foundation59.6%Max—Only one result
ARC-AGI-3ARC Prize Foundation0.2%Max—Only one result
AA Intelligence IndexArtificial Analysis52.3intelligence-index55.8intelligence-indexQwen3.8 Flash
AA Terminal-Bench 2.1Artificial Analysis80.9%terminal-bench-2.186.1%terminal-bench-2.1Qwen3.8 Flash
AA Humanity's Last ExamArtificial Analysis39.5%humanitys-last-exam38.0%humanitys-last-examGPT-5.6 Luna
Terminal-Bench 4.0Terminal-Bench (Laude Institute)17.3%14.4%–20.1%Codex · Max—Only one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

GPT-5.6 Luna vs Qwen3.8 Flash: common questions

Is GPT-5.6 Luna better than Qwen3.8 Flash?

Qwen3.8 Flash ranks higher on the ModelCap Index as of 3 September 2026: #17 against #18. 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.

Is GPT-5.6 Luna cheaper than Qwen3.8 Flash?

Qwen3.8 Flash is cheaper on output tokens: $0.47/1M against $1.20/1M. Input tokens are $0.20/1M for GPT-5.6 Luna and $0.15/1M for Qwen3.8 Flash. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, GPT-5.6 Luna or Qwen3.8 Flash?

Both publish a 1M-token context window.

Which is better for coding, GPT-5.6 Luna or Qwen3.8 Flash?

AA Terminal-Bench 2.1: GPT-5.6 Luna 80.9%, Qwen3.8 Flash 86.1% — Qwen3.8 Flash leads.

Are GPT-5.6 Luna and Qwen3.8 Flash open-weight models?

GPT-5.6 Luna: API only. Qwen3.8 Flash: Restricted license. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run GPT-5.6 Luna and Qwen3.8 Flash?

ModelCap currently lists 3 API providers for GPT-5.6 Luna and 1 for Qwen3.8 Flash, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this GPT-5.6 Luna vs Qwen3.8 Flash comparison?

Every figure comes from the sealed ModelCap dataset published 3 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.

Explore further