Which is cheaper, DeepSeek-V4-Flash-Max or GPT-5.1 Instant?
As of August 20, 2026, DeepSeek-V4-Flash-Max is 96% cheaper on blended LLM API pricing. DeepSeek-V4-Flash-Max costs $0.14 per million input tokens and $0.28 per million output tokens ($0.42 blended 1M-in + 1M-out). GPT-5.1 Instant costs $1.25 / $10.00 per million tokens ($11.25 blended). Sources: https://api-docs.deepseek.com/quick_start/pricing and https://developers.openai.com/api/docs/pricing. The cheapest LLM for your app still depends on how many output tokens you generate.
How much does DeepSeek-V4-Flash-Max vs GPT-5.1 Instant cost per million tokens?
DeepSeek-V4-Flash-Max DeepSeek API pricing is $0.14 input and $0.28 output per million tokens via DeepSeek. GPT-5.1 Instant OpenAI API pricing is $1.25 input and $10.00 output per million tokens via OpenAI. Use those four numbers, not ChatGPT Plus or Claude Pro subscription prices, when you are comparing APIs.
Which is better for coding, DeepSeek-V4-Flash-Max or GPT-5.1 Instant?
DeepSeek-V4-Flash-Max leads on SWE-bench Verified: DeepSeek-V4-Flash-Max at 79% vs GPT-5.1 Instant at 76.3%. SWE-bench measures real GitHub fixes; LiveCodeBench measures contest programming.
What is the context window for DeepSeek-V4-Flash-Max vs GPT-5.1 Instant?
DeepSeek-V4-Flash-Max supports a 1M token context window, while GPT-5.1 Instant supports 400K tokens. DeepSeek-V4-Flash-Max offers a larger context window. Filling a larger window bills more input tokens, so the cheaper-per-million model can still cost more on long documents.
Which model performs better on benchmarks, DeepSeek-V4-Flash-Max or GPT-5.1 Instant?
DeepSeek-V4-Flash-Max leads on 2 of 2 shared benchmarks versus GPT-5.1 Instant's 0 wins. Check the comparison table for GPQA Diamond, SWE-bench, MMLU, HLE, and the other evals we track. Token price and benchmark score together are the usual LLM comparison, not either number alone.
Is DeepSeek-V4-Flash-Max or GPT-5.1 Instant better for production use?
Both DeepSeek-V4-Flash-Max and GPT-5.1 Instant are production API models. For cost-sensitive production traffic, DeepSeek-V4-Flash-Max has better economics on the blended 1M-in + 1M-out scale. For maximum capability, weight the benchmark table for your domain. Many production stacks route cheap models for drafts and a frontier model for the hard turn, which is usually cheaper than sending everything to the expensive API.
Can I switch between DeepSeek-V4-Flash-Max and GPT-5.1 Instant in my app?
Yes. Call DeepSeek-V4-Flash-Max through DeepSeek and GPT-5.1 Instant through OpenAI with separate API keys, or through a gateway that already wraps both. Keep prompts in tokens, not characters, when you estimate the invoice. AnotherWrapper templates can swap providers without rewriting auth and billing.
How accurate is this DeepSeek-V4-Flash-Max vs GPT-5.1 Instant pricing data?
List rates are the latest published DeepSeek API pricing and OpenAI API pricing, quoted per million tokens. Official rate sheets: https://api-docs.deepseek.com/quick_start/pricing and https://developers.openai.com/api/docs/pricing. Prompt caching, batch APIs, and committed-use discounts can change the invoice. Benchmark scores are from official publications and independent evals, updated as new numbers land.
What is the output token limit for DeepSeek-V4-Flash-Max and GPT-5.1 Instant?
DeepSeek-V4-Flash-Max supports up to 393K output tokens per request, while GPT-5.1 Instant supports up to 128K output tokens. Output tokens are usually the expensive half of API pricing, so a higher max output cap is a capability, not a discount.
Which model has better throughput, DeepSeek-V4-Flash-Max or GPT-5.1 Instant?
GPT-5.1 Instant has a measured throughput of approximately 100 tokens/second. Throughput data for DeepSeek-V4-Flash-Max is not yet available. Throughput (tokens per second) and time-to-first-token are why two models with the same per-million-token price can still feel different in chat and agents.
How do I switch the models in this DeepSeek-V4-Flash-Max vs GPT-5.1 Instant comparison?
Use the model pickers at the top of this LLM comparison. Search any model in the index and the URL updates. Open DeepSeek-V4-Flash-Max or GPT-5.1 Instant from the sidebar for the single-model API pricing page, or go back to the LLM pricing table to sort by cheapest blended cost.
