Model comparison
Compare GPT-5.6 Luna and DeepSeek-V4-Flash using the same provider-sourced text & reasoning rubric. No mystery score and no invented benchmark ranking.
Facts checked September 14, 2026
Set your usage. Your estimate updates as you type.
Example: 6,000 input tokens for 10 pages, plus a 500-token summary. Page lengths vary; adjust the numbers below.
One run sends your input to the model once and receives an answer. Tokens are pieces of text: input is what you send, output is the answer you receive.
Estimates exclude taxes, tools, cache storage/writes, free allowances and custom discounts. Image estimates cover output only, not prompt or reference-image charges. Quality modes differ by model. Unlisted settings are not treated as free.
| Model | Access | Estimated total (USD) |
|---|---|---|
| GPT-5.6 LunaOpenAI | OpenAI | $0.0018 |
| DeepSeek-V4-FlashDeepSeek | DeepSeek | No reviewed rate |
Quick take
The budget GPT-5.6 tier for processing many short, repeatable tasks.
Low token prices do not guarantee a low task cost if the model needs retries or extensive reasoning.
DeepSeek's lower-cost V4 model for high-volume reasoning, coding, agents, and million-token text workloads.
Flash's knowledge cutoff and universal latency are not published. Do not confuse it with Flash-Vision-Exp, and verify peak pricing, cache behavior, output budgets, jurisdiction, and data handling.
Compare the published facts
Values use each provider's own published units and limits. A blank means the provider did not publish a directly comparable value in the sources reviewed.
| Text & reasoning | GPT-5.6 Luna | DeepSeek-V4-Flash |
|---|---|---|
| Context windowMaximum combined prompt and working context documented by the provider. | 1.05M tokens | 1M tokens |
| Maximum outputProvider-published response limit, where available. | 128K tokens | Up to 384K tokens |
| Knowledge cutoffLatest reliable knowledge date explicitly published by the model provider. Search and connected tools can retrieve newer information but do not change the model's built-in cutoff. | February 16, 2026 | Not published |
| Input priceCurrent standard list price per million input tokens unless noted. | $0.2 / 1M | $0.44 / 1M peak uncached; $0.22 off-peak |
| Output priceCurrent standard list price per million output tokens unless noted. | $1.2 / 1M | $1.32 / 1M peak; $0.66 off-peak |
| InputsMedia types accepted by the listed model endpoint. | Text, image | Text; separate Flash-Vision-Exp accepts images |
| Tools & agentsSelected native tools and agent-building capabilities, not an exhaustive list. | Functions, web/file search, code, computer, MCP | Tools, JSON output, Responses API, thinking effort, FIM beta |
How to choose
Start with the job you need to complete, then validate cost, access, and policy details on your exact provider route.
OpenAI says API inputs and outputs are not used for model training by default. Default abuse-monitoring logs may be retained for up to 30 days; qualifying organizations can request other controls.
Provider and API links
DeepSeek documents its Responses API as stateless and says responses and conversations are not stored by that endpoint. This is not a complete account-wide retention or training-use promise; review current platform terms and automatic cache behavior for sensitive data.
Provider and API links
Frequently asked questions
GPT-5.6 Luna: The budget GPT-5.6 tier for processing many short, repeatable tasks. DeepSeek-V4-Flash: DeepSeek's lower-cost V4 model for high-volume reasoning, coding, agents, and million-token text workloads.
Consider GPT-5.6 Luna when your priority is Data extraction. Consider DeepSeek-V4-Flash when your priority is Cost-efficient coding and agent workloads. Test both with your own data and provider route before committing.
No. This comparison aligns provider-published facts for the Text & reasoning category. It does not claim a universal winner or combine incompatible third-party benchmark scores.
