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AI Choice Engine

Model comparison

DeepSeek V3.1 vs GPT-5.6 Luna

DeepSeek against OpenAI, compared on context, price, and attributed benchmark results.

Recorded profile verification October 1, 2026Individual provider fields may changeEvidence confidence: Insufficient data — see receipts below

DeepSeek

DeepSeek V3.1

Budget · Open weights

vs

OpenAI

GPT-5.6 Luna

Budget

AI model capability comparison
SpecificationDeepSeek V3.1GPT-5.6 Luna
ProviderDeepSeekOpenAI
TierBudgetBudget
Context window128KWinner: 1.05M
Max outputNot verifiedUnverified128K
Input / 1M tokensNot verifiedUnverified$0.20
Output / 1M tokensNot verifiedUnverified$1.20
WeightsOpenClosed
Parameters671B total / 37B active (MoE)Not verifiedUnverified
Reasoning levelsNot verifiedUnverifiednone, low, medium, high, xhigh, max
Modalitiestexttext, image
LicenseMITNot verifiedUnverified
API model idNot verifiedUnverifiedgpt-5.6-luna
ReleasedAugust 21, 2025July 9, 2026
Terminal-Bench 2.1 · source date GPT-5.6 Luna: 2026-07-09Not verifiedUnverified84.7
LiveBench · source date GPT-5.6 Luna: 2026-09-05Not verifiedUnverified73.6

Dates beside benchmark scores refer to the linked source’s publication or capture date unless that source explicitly states when it measured the result. A shared URL alone does not establish comparable runs; unverified setups are marked. Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.

Benchmark receipts

Where each score comes from, and how far it can be compared across models.

Pricing tiers

DeepSeek V3.1: No current first-party API or verified third-party tariff. deepseek-chat moved to V3.1-Terminus on September 22, 2025; that alias later retired July 24, 2026. MIT weights remain for self-hosting or separately priced hosts. The original checkpoint's hard output cap and selectable hosted effort menu remain unverified.

GPT-5.6 Luna: Launch $1/$6, reduced to $0.20/$1.20 on July 30. Above 272K input the full request bills $0.40/$1.80. Cached input $0.02; cache writes $0.25 at short context. Batch $0.10/$0.60 at short context. Regional/FedRAMP processing adds 10% where eligible.

BudgetOpen weightsRecord checked October 1, 2026

DeepSeek V3.1

DeepSeek V3.1 is a legacy open-weight (MIT) 671B/37B MoE with a 128K context — superseded by V3.1-Terminus, V3.2 and then V4.

Best for

  • Cost-sensitive hosted agents
  • High-volume coding assist
  • Open-weight deployments

Watch out

Legacy: DeepSeek's first-party alias moved to V3.1-Terminus on September 22, 2025. Pin the exact V3.1 checkpoint; current hosted rates depend on provider. The original card supports thinking/non-thinking templates, not a verified selectable low/high/max menu. Self-hosting memory depends on quantization, offloading and hardware.

BudgetRecord checked October 1, 2026

GPT-5.6 Luna

OpenAI’s GPT-5.6 budget tier, succeeded by GPT-6 Luna on September 22. The newer model halves input pricing ($0.20→$0.10) and lowers output pricing from $1.20 to $0.50.

Best for

  • Classification
  • High-volume chat
  • Latency-sensitive pipelines

Watch out

Superseded by GPT-6 Luna and still listed in the API. Historical index captures are not current evidence of equal quality; the successor has lower Standard input and output prices.

When the cheaper one wins

One of these rows is missing a verified output price, so this page will not name a cheaper winner. Run the model picker against the actual job instead of guessing.

Run the model picker

Evidence confidence: Insufficient data

How strong and complete the evidence behind this comparison is — not a prediction of which model is better. Hard limitations apply: missing pricing; evidence too sparse.

  • Pricing incomplete — No verified token pricing for DeepSeek V3.1.
  • 2/5 core specs verified on both sides — Not published for at least one side: max output, parameter count, reasoning levels.
  • No directly aligned benchmark setup — No benchmark has matching cited sources, source dates, units, effort and recorded run details on both models.
  • Verified within the last 90 days — Older of the two catalog checks was 25 days ago.
  • Both models carry source citations — Each side has at least two catalog sources on record.

Source receipts

Each catalog figure was checked against the provider or an independent second source on the date shown.

Related comparisons

Diving deeper on one model? DeepSeek V3.1 · GPT-5.6 Luna

Common questions

DeepSeek V3.1 vs GPT-5.6 Luna

Answered from the verified figures on this page rather than general guidance.

Which has the larger context window, DeepSeek V3.1 or GPT-5.6 Luna?
GPT-5.6 Luna accepts 1.05M tokens against 128K for DeepSeek V3.1. This only matters if you routinely send very long documents or large codebases.
Should I use DeepSeek V3.1 or GPT-5.6 Luna?
Both are classified in our budget tier; this editorial grouping does not imply equal capability. DeepSeek V3.1 is a candidate for cost-sensitive hosted agents; GPT-5.6 Luna is a candidate for classification. Compare accuracy, tool reliability, latency and cost on representative tasks.
Can I self-host DeepSeek V3.1 or GPT-5.6 Luna?
DeepSeek V3.1 publishes open weights, but self-hosting and third-party provider access depend on the licence, hardware, serving support, and availability. GPT-5.6 Luna is a closed model whose supported access paths are controlled by its provider.

Next step

Choosing between them

The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.

  • Context: GPT-5.6 Luna takes 1.05M against 128K for DeepSeek V3.1 — only decisive if your prompts approach the smaller window.
  • Deployment: DeepSeek V3.1 publishes weights you can self-host; the other is API-only.
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