API cost decision in 10 seconds

🔥DeepSeek V4.1 Flash vs GPT Luna Latest

The standard workload cost is tied; choose by context window, provider fit, latency, or model quality.

Page updated: 2026-10-27T00:08:09Z Data confirmed: 2026-10-28T05:08:04Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

The standard workload cost is tied; choose by context window, provider fit, latency, or model quality.

Both models are estimated at $0.35 for the standard 1M input plus 500K output workload.

Cost-first pickTie

Context-first pickGPT Luna Latest

Sample savings$00%

10x traffic gap$0

Context-window winner: GPT Luna Latest. Cost does not separate this pair on the standard workload, so the next decision point is context window and model behavior.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Cost winner changes by workload shape: input-heavy / RAG favors GPT Luna Latest, balanced workload favors DeepSeek V4.1 Flash, and output-heavy chatbot favors DeepSeek V4.1 Flash.

Workload shape	Token mix	Better pick	DeepSeek V4.1 Flash	GPT Luna Latest
Input-heavy / RAG	5M input + 500K output	GPT Luna Latest	$0.91	$0.75
Balanced workload	1M input + 1M output	DeepSeek V4.1 Flash	$0.56	$0.6
Output-heavy chatbot	1M input + 5M output	DeepSeek V4.1 Flash	$2.24	$2.6

Cheaper input GPT Luna Latest $0.14 vs $0.1 / 1M

GPT Luna Latest is $0.04 cheaper per 1M input tokens (28.6% lower; 1.4x difference).

Cheaper output DeepSeek V4.1 Flash $0.42 vs $0.5 / 1M

DeepSeek V4.1 Flash is $0.08 cheaper per 1M output tokens (16% lower; 1.19x difference).

Larger context GPT Luna Latest 1.05M vs 1.05M

GPT Luna Latest has 1.42K more context (1x larger).

Sample workload Tie $0.35 vs $0.35

Both models have the same estimated cost for the standard 1M input plus 500K output workload: $0.35.

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

DeepSeek V4.1 Flash Calculating… Estimated API cost

GPT Luna Latest Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

GPT Luna Latest has the lower input price; DeepSeek V4.1 Flash has the lower output price; GPT Luna Latest offers the larger context window. For the 1M input plus 500K output sample, the standard workload cost is tied.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.35 for DeepSeek V4.1 Flash and $0.35 for GPT Luna Latest.

Best Fit

Choose DeepSeek V4.1 Flash when you care most about lower output-token price.

Choose GPT Luna Latest when you care most about lower input-token price, and larger context window.

Decision Notes

Both models are estimated at $0.35 for the standard 1M input plus 500K output workload.
Both models have the same estimated cost for the standard 1M input plus 500K output workload: $0.35.
GPT Luna Latest is $0.04 cheaper per 1M input tokens (28.6% lower; 1.4x difference).
DeepSeek V4.1 Flash is $0.08 cheaper per 1M output tokens (16% lower; 1.19x difference).
GPT Luna Latest has 1.42K more context (1x larger).

Head-to-Head Specs

Feature	🔥DeepSeek V4.1 Flash (DeepSeek)	GPT Luna Latest (OpenAI)
Input Price prompt tokens per 1M	$0.14	$0.1
Completion Price per 1M tokens	$0.42	$0.5
Sample Workload Cost 1M input + 500K output	$0.35	$0.35
Context Window	1.05M	1.05M
Release Date	2026-09-10	2026-09-11
Popularity	#3

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Tie	Both models are estimated at $0.35 for the standard 1M input plus 500K output workload.
High-volume input processing	GPT Luna Latest	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	DeepSeek V4.1 Flash	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	GPT Luna Latest	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

DeepSeek V4 Flash 0731 (free) can replace DeepSeek V4.1 Flash when lower sample workload cost matters most: $0.
DeepSeek V4 Flash (free) can replace DeepSeek V4.1 Flash when lower sample workload cost matters most: $0.
DeepSeek V4.1 Flash (batch) can replace DeepSeek V4.1 Flash when lower sample workload cost matters most: $0.12.
DeepSeek V4 Flash Latest can replace DeepSeek V4.1 Flash when lower sample workload cost matters most: $0.13.

Larger context near this budget

Llama 4 Scout offers 1.31M context with $0.25 sample workload cost.

Popular competitors

Kimi K3.1 Pro · MoonshotAI · #1
DeepSeek V4.1 Flash 1017 · DeepSeek · #2
GLM 5.3 Flash · Z.ai · #4
GPT-6 Luna · OpenAI · #5

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

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Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

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DeepSeek catalog

Review all tracked DeepSeek models before deciding whether this matchup is the right shortlist.

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OpenAI catalog

Check other OpenAI models with comparable pricing, context, or release timing.

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DeepSeek V4.1 Flash

DeepSeek V4.1 Flash is a sparse mixture-of-experts model from DeepSeek, and the first built on the company's Causal Encoder-Decoder (CED) architecture. It activates 8B parameters on input and 16B on...

GPT Luna Latest

This model always redirects to the latest model in the GPT Luna family.