Model comparison

DeepSeek V4.1 Flash vs GPT-6 Luna

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

Catalog record checked September 26, 2026Individual provider fields may changeEvidence confidence: High — see receipts below

DeepSeek

DeepSeek V4.1 Flash

Balanced · Open weights

OpenAI

GPT-6 Luna

Budget

AI model capability comparison
Specification	DeepSeek V4.1 Flash	GPT-6 Luna
Provider
Provider	DeepSeek	OpenAI
Tier
Tier	Balanced	Budget
Context window
Context window	1M	Winner: 1.05M
Max output
Max output	Winner: 384K	128K
Input / 1M tokens
Input / 1M tokens	$0.30	Winner: $0.10
Output / 1M tokens
Output / 1M tokens	$1.20	Winner: $0.50
Weights
Weights	Open	Closed
Parameters
Parameters	552B MoE (causal encoder-decoder; 8B active for input, 16B for output)	GPT-6 low-cost tier
Reasoning levels
Reasoning levels	low, high, max	none, low, medium, high, xhigh, max
Modalities
Modalities	text, image	text, image
License
License	MIT	Not disclosedUnverified
API model id
API model id	deepseek-flash	gpt-6-luna
Released
Released	September 10, 2026	September 22, 2026
Artificial Analysis Intelligence Index [max] (2026-09-26)
Artificial Analysis Intelligence Index [max] (2026-09-26)	Winner: 39.5	37.3
DeepSWE 1.1 [max] (2026-09-10)
DeepSWE 1.1 [max] (2026-09-10)	Winner: 74.2	66.6
Terminal-Bench 2.1 [max] (2026-09-10)
Terminal-Bench 2.1 [max] (2026-09-10)	90.6	Not verifiedUnverified
GPQA Diamond [max] (2026-09-10)
GPQA Diamond [max] (2026-09-10)	90.9	Not verifiedUnverified

Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. 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.

2026-09-26
Artificial Analysis
Composite index blending reasoning, knowledge, and coding evals into one 0–100 score.
Comparable with caveatOnly same-version scores are comparable. v4.3.2 was rebaselined (the top score fell from 66 on v4.1.1 to ~58), so v4.1.1 figures must not be compared with v4.3.2 figures — check measuredAt.
2026-09-22
OpenAI — Introducing GPT-6 Sol and Luna (vendor; not yet on Datacurve's board)
Agentic software engineering: pass@1 on real repo tasks with reported cost per completed task.
Directly comparable
2026-09-10
DeepSeek V4.1-Flash release notes (vendor)
Agentic software engineering: pass@1 on real repo tasks with reported cost per completed task.
Directly comparable

Pricing tiers

DeepSeek V4.1 Flash: Official peak rates $0.30/$1.20 per MTok; off-peak $0.15/$0.60 (50% of peak). Cache hit $0.006 peak / $0.003 off-peak. Peak hours are weekdays 01:00–04:00 and 06:00–10:00 UTC. Open weights (MIT). The legacy deepseek-v4-flash and deepseek-v4-flash-vision-exp ids temporarily route here.

GPT-6 Luna: Direct successor to GPT-5.6 Luna at half the price. Cached input $0.01/MTok; cache writes $0.125. Above 272K input the whole request bills $0.20/$0.75 ($0.02 cached). Batch/Flex $0.05/$0.25; Fast mode $0.20/$1.00. Knowledge cutoff May 18 2026.

BalancedOpen weightsRecord checked September 26, 2026

DeepSeek V4.1 Flash

DeepSeek V4.1 Flash is DeepSeek's new default — an open-weight (MIT) multimodal MoE that DeepSeek says beats V4-Pro on performance, cost and speed.

Best for

Open-weight price-performance
High-volume hosted agents
Self-hosting with MIT weights

Watch out

Vendor benchmark claims are far ahead of its independent Artificial Analysis score (39.5 on v4.3.2); peak/off-peak billing means the hour you run matters.

BudgetRecord checked September 26, 2026

GPT-6 Luna

GPT-6 Luna is OpenAI's cheapest current model at $0.10/$0.50 — the direct successor to GPT-5.6 Luna at half the price, with the full 1.05M-token context.

Best for

High-volume chat and extraction
Classification
Cost-capped agent loops

Watch out

Small tier: it matches GPT-5.6 Luna on the Artificial Analysis index but sits well below GPT-6 Sol on hard reasoning; the DeepSWE figure is vendor-reported at max effort.

When the cheaper one wins

GPT-6 Luna is cheaper on output at $0.50 per million tokens against $1.20 for DeepSeek V4.1 Flash — about 2.4×. Use the cheaper tier for classification, extraction, summarisation, and any task where the expensive model’s extra score does not change the accepted output. The expensive one only pays if your hardest task actually fails on the cheap tier. These are standard-tier API rates, excluding batch and cache discounts.

Run the model picker

Evidence confidence: High

How strong and complete the evidence behind this comparison is — not a prediction of which model is better.

Pricing verified on both sides — Input and output rates are verified for both models.
5/5 core specs verified on both sides — All core specifications verified for both models.
2 shared named benchmarks with differing scores — Measured on: Artificial Analysis Intelligence Index, DeepSWE 1.1.
Verified within the last 90 days — Newest catalog check was 2 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.

DeepSeek V4.1 Flash: DeepSeek — V4.1-Flash release (2026-09-10) (accessed 2026-09-26)
DeepSeek V4.1 Flash: DeepSeek API pricing (deepseek-flash $0.30/$1.20 peak) (accessed 2026-09-26)
DeepSeek V4.1 Flash: Hugging Face — deepseek-ai/DeepSeek-V4.1-Flash (accessed 2026-09-26)
GPT-6 Luna: OpenAI — Introducing GPT-6 Sol and Luna (accessed 2026-09-26)
GPT-6 Luna: OpenAI model docs — gpt-6-luna (1.05M context, 128K output) (accessed 2026-09-26)
GPT-6 Luna: OpenAI API pricing (gpt-6-luna $0.10/$0.50, cached $0.01) (accessed 2026-09-26)

Related comparisons

Diving deeper on one model? DeepSeek V4.1 Flash · GPT-6 Luna

Common questions

DeepSeek V4.1 Flash vs GPT-6 Luna

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

Is DeepSeek V4.1 Flash or GPT-6 Luna cheaper for input?

GPT-6 Luna is cheaper at $0.10 per million input tokens, against $0.30 for DeepSeek V4.1 Flash — roughly 3.0× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; DeepSeek V4.1 Flash has tiered pricing: Official peak rates $0.30/$1.20 per MTok; off-peak $0.15/$0.60 (50% of peak). Cache hit $0.006 peak / $0.003 off-peak. Peak hours are weekdays 01:00–04:00 and 06:00–10:00 UTC. Open weights (MIT). The legacy deepseek-v4-flash and deepseek-v4-flash-vision-exp ids temporarily route here. GPT-6 Luna has tiered pricing: Direct successor to GPT-5.6 Luna at half the price. Cached input $0.01/MTok; cache writes $0.125. Above 272K input the whole request bills $0.20/$0.75 ($0.02 cached). Batch/Flex $0.05/$0.25; Fast mode $0.20/$1.00. Knowledge cutoff May 18 2026.

Is DeepSeek V4.1 Flash or GPT-6 Luna cheaper for output?

GPT-6 Luna is cheaper at $0.50 per million output tokens, against $1.20 for DeepSeek V4.1 Flash — roughly 2.4× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; DeepSeek V4.1 Flash has tiered pricing: Official peak rates $0.30/$1.20 per MTok; off-peak $0.15/$0.60 (50% of peak). Cache hit $0.006 peak / $0.003 off-peak. Peak hours are weekdays 01:00–04:00 and 06:00–10:00 UTC. Open weights (MIT). The legacy deepseek-v4-flash and deepseek-v4-flash-vision-exp ids temporarily route here. GPT-6 Luna has tiered pricing: Direct successor to GPT-5.6 Luna at half the price. Cached input $0.01/MTok; cache writes $0.125. Above 272K input the whole request bills $0.20/$0.75 ($0.02 cached). Batch/Flex $0.05/$0.25; Fast mode $0.20/$1.00. Knowledge cutoff May 18 2026.

Which has the larger context window, DeepSeek V4.1 Flash or GPT-6 Luna?

GPT-6 Luna accepts 1.05M tokens against 1M for DeepSeek V4.1 Flash. This only matters if you routinely send very long documents or large codebases.

Do DeepSeek V4.1 Flash and GPT-6 Luna support the same reasoning levels?

DeepSeek V4.1 Flash exposes low, high, max, while GPT-6 Luna exposes none, low, medium, high, xhigh, max.

Should I use DeepSeek V4.1 Flash or GPT-6 Luna?

DeepSeek V4.1 Flash is the balanced tier and GPT-6 Luna the budget tier. The useful question is whether your hardest task actually fails on the cheaper one — most production volume such as classification, extraction and summarisation does not.

Can I self-host DeepSeek V4.1 Flash or GPT-6 Luna?

DeepSeek V4.1 Flash publishes open weights, but self-hosting and third-party provider access depend on the licence, hardware, serving support, and availability. GPT-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.

Input price: GPT-6 Luna costs $0.10 per 1M tokens versus $0.30 for DeepSeek V4.1 Flash — a 3x difference at the headline tier.
Context: GPT-6 Luna takes 1.05M against 1M for DeepSeek V4.1 Flash — only decisive if your prompts approach the smaller window.
Measured capability: DeepSeek V4.1 Flash leads Artificial Analysis Intelligence Index 39.5 to 37.3 (measured 2026-09-26).
Deployment: DeepSeek V4.1 Flash publishes weights you can self-host; the other is API-only.
Positioning: DeepSeek V4.1 Flash sits in the balanced tier, GPT-6 Luna in the budget tier — most production volume (classification, extraction, summarisation) does not need the pricier tier.

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