DeepSeek V4 Flash vs V4.1 Flash
V4 Flash is the old id. DeepSeek’s first-party docs now tell you to call deepseek-flash for V4.1 Flash. On this site the current id is deepseek-v4.1-flash. The old slug stays so existing configs keep working.
DeepSeek V4 Flash is still callable on llmrelay and still sold, but superseded. The comparison below is accurate; just know there is a newer generation if you are starting fresh.
Input / M (llmrelay): DeepSeek cache-miss list for V4.1 Flash is $0.15/$0.60 off-peak and $0.30/$1.20 peak. We bill one flat rate 24/7.
Model id on llmrelay: DeepSeek first-party uses deepseek-flash for V4.1. The expires-on-0910 preview id is dead.
DeepSeek status: api-docs.deepseek.com/updates, fetched 2026-09-11. First-party still accepts deepseek-v4-flash and routes it to V4.1 Flash.
Prices are llmrelay's, at 50% of official list. Specs are the vendor's own published figures (Anthropic model docs), not our benchmarks. We do not publish scores we cannot source.
Use deepseek-v4-flash when
- +A config, eval set, or contract already names this exact id and you do not want to re-check output.
- +You landed on the old URL from search and just need the same cheap Flash rate. It still bills $0.19/$0.54 here.
Use deepseek-v4.1-flash when
- +You are starting new Flash work. This is the current id on llmrelay.
- +You saw DeepSeek’s 10 September GA and want the current Flash, not the retired V4 Flash name.
- +You tried the 09-08 expires-on-0910 preview. That name is gone. This is the replacement.
The honest answer
Same invoice, same upstream model. New work: deepseek-v4.1-flash. Keep deepseek-v4-flash only to pin an old config. One prepaid key covers both, plus Opus 5 and GPT-6 Astra.
What this costs you per month
At 50M input and 5M output tokens a month — a realistic heavy agent workload.
Struck-through column is the vendor's list price for the same traffic. Adjust the numbers on the calculator.
One key covers both
Switching between them is a model-id change, not a new account. Prepaid, no subscription, $10 minimum — enough to run the same prompt through both and settle the argument with your own output.
Next steps on this decision
Per-model detail for both sides, and the adjacent comparisons people usually read alongside this one.
- DeepSeek V4 Flash pricing and specs$0.19/M in, $0.54/M out — half list. Previous Flash id. Still callable here. DeepSeek retired it; new work should use V4.1 Flash.
- DeepSeek V4.1 Flash pricing and specs$0.19/M in, $0.54/M out — half list. Current DeepSeek Flash. Official GA 10 September 2026. Flat $0.19/$0.54 here, no peak surcharge.
- V4.1 Flash vs Sonnet 5 — cheap bulk vs Anthropic defaultV4.1 Flash is the current DeepSeek Flash, GA 10 September 2026.
- Cost calculatorPut your own monthly token volume in and see the bill against vendor list price.
- Full price listEvery model we serve, at 50% of official list. No subscription, no volume gate.
- All comparisonsModel-vs-model and gateway-vs-gateway, with sourced specs only.