Quick Verdict
| Need | Better first pick | Why |
|---|---|---|
| Output-heavy or cached text work | DeepSeek V4.1 Flash | The September cut improves both fresh-token and repeated-prefix economics |
| Low-cost OpenAI route | GPT-4.1 nano or GPT-6 Luna | Keep the OpenAI toolchain while reserving larger models for failed tasks |
| Budget escalation | Test V4 Pro against GPT-6 Luna | Quality, retries, and traffic hours decide the cheaper accepted result |
| Stronger OpenAI reasoning | GPT-6 Sol | A mature premium route without jumping to the flagship tier |
| Frontier reasoning | GPT-6 Astra | Use only where its quality gain repays the much higher live rate |
For live model tables, use DeepSeek pricing, OpenAI pricing, and the token calculator. The DeepSeek API pricing guide covers the provider in more depth.
How DeepSeek Billing Works Now
DeepSeek released V4.1 Flash on September 10 and kept the deepseek-flash endpoint, so most clients do not need a model-name migration. Peak windows still run from 01:00–04:00 UTC and 06:00–10:00 UTC, Monday through Friday. Weekday hours outside those windows and every hour on Saturday and Sunday use the off-peak tier.
Against the immediately preceding V4 Flash schedule, V4.1 cut input by about 32%, cached input by about 57%, and output by about 9% across both tiers. Peak rates remain twice the off-peak rates. The live table and chart above are generated from today’s pricing.json; DeepSeek confirms the release and effective time in its V4.1 announcement and publishes the complete schedule in its official pricing documentation.
The cut strengthens Flash against OpenAI’s small routes, but it does not make every task cheaper. GPT-4.1 nano and GPT-6 Luna can still win on some input-heavy workloads, while V4 Pro must prove a quality or retry advantage. GPT-6 Astra belongs in the comparison as OpenAI’s current flagship, not as the default route for bulk traffic.
Cost Scenarios
| Scenario | Token mix | Cheapest likely route | Why |
|---|---|---|---|
| Support bot | Many short chats | V4.1 Flash or GPT-6 Luna | Output length, weekday traffic hour, and first-pass resolution decide the winner |
| Document summaries | Heavy input, shorter output | Small OpenAI first | Lower uncached input can outweigh DeepSeek’s output advantage |
| Coding assistant | Large input and output | Test V4.1 Flash, V4 Pro, and GPT-6 Luna | Quality and retries matter more than the sticker price |
| Cached agent context | Repeated prompts and schemas | V4.1 Flash off-peak | The new cache rate rewards stable prefixes, but only when they actually hit |
| Difficult reasoning | Low-volume, high-value tasks | GPT-6 Sol or GPT-6 Astra | Escalate only after a cheaper route fails an evaluation or confidence check |
The real comparison is cost per accepted answer. If DeepSeek needs more retries, longer prompts, or extra review, the savings shrink. If it passes evals, the savings compound quickly.
What You Give Up With DeepSeek
OpenAI still has the stronger ecosystem: SDK familiarity, third-party integrations, enterprise procurement, and a deeper premium ladder. V4.1 Flash adds native multimodal support, but teams should test its exact image inputs and tool behavior before assuming feature parity. DeepSeek is strongest when quality is measurable and cost is the constraint.
If you want a managed open-model fallback instead of relying on one direct provider, compare Novita’s current model catalog on the same evaluation set.
Affiliate disclosure: AI Pricing Guru may earn a commission from the sponsored link above at no extra cost to you. It does not affect our recommendations.
Routing Pattern
| Workload | Default route | Escalation route |
|---|---|---|
| Classification or tagging | GPT-4.1 nano or V4.1 Flash | GPT-6 Luna |
| Support drafts | V4.1 Flash | GPT-6 Luna or V4 Pro |
| RAG answers | V4.1 Flash or V4 Pro | GPT-6 Sol |
| Coding triage | V4.1 Flash | GPT-6 Luna or V4 Pro |
| Hard code changes | Test V4 Pro and GPT-6 Luna | GPT-6 Sol, then GPT-6 Astra |
FAQ
Is DeepSeek still cheaper than OpenAI?
Against GPT-6 Sol and GPT-6 Astra, usually yes on token spend. Against GPT-4.1 nano or GPT-6 Luna, the answer depends on the UTC billing window, token mix, cache hits, retries, and task success rate. DeepSeek stays off-peak throughout the weekend.
What changed with DeepSeek V4.1 Flash?
DeepSeek kept the deepseek-flash endpoint, added V4.1 capabilities, and lowered all three token categories on September 10. Peak and off-peak windows remain in place, so deployment time still affects the bill.
Should I replace GPT-6 Astra with DeepSeek?
Not blindly. Use V4.1 Flash for bulk work that passes your evaluations, then keep GPT-6 Sol or GPT-6 Astra as an escalation route where quality risk is high.
Which model should startups test first?
Start with DeepSeek V4.1 Flash, GPT-6 Luna, and your current production default; add V4 Pro or a premium OpenAI route only when harder tasks justify it. Route based on accepted-result cost, not provider loyalty.
Bottom Line
DeepSeek V4.1 Flash is the budget-first route for output-heavy and cache-heavy work that passes your evaluations. GPT-4.1 nano and GPT-6 Luna remain credible low-cost OpenAI defaults, while GPT-6 Sol and GPT-6 Astra should be gated escalation tiers. Choose with the live rate table, your actual traffic schedule, and cost per accepted result.