GPT-5 vs DeepSeek-V4-Flash
OpenAI vs DeepSeek · Prices checked 12 August 2026
On blended cost DeepSeek-V4-Flash undercuts GPT-5 by about 21.3×: $0.182 per million tokens versus $3.88. A single 100K-input, 10K-output job costs $0.017 on DeepSeek-V4-Flash against $0.225 on GPT-5.
On context, DeepSeek-V4-Flash is the larger at 1,000,000 tokens versus 400,000. GPT-5 was released 2025; DeepSeek-V4-Flash Jul 2026.
Pricing and capacity
| Metric | GPT-5 | DeepSeek-V4-Flash | Difference |
|---|---|---|---|
| Input / 1M tokens | $1.25 | $0.140 | 8.9× |
| Output / 1M tokens | $10.00 | $0.280 | 35.7× |
| Blended · 70/30calculated | $3.88 | $0.182 | 21.3× |
| Blended · 50/50calculated | $5.63 | $0.210 | 26.8× |
| Blended · 80/20calculated | $3.00 | $0.168 | 17.9× |
| Blended · 20/80calculated | $8.25 | $0.252 | 32.7× |
| Job cost · 100K + 10Kcalculated | $0.225 | $0.017 | 13.4× |
| Job cost · 1M + 100Kcalculated | $2.25 | $0.168 | 13.4× |
| Context window | 400,000 | 1,000,000 | 2.5× |
Input and output rates are as published by each provider. Blended and job-cost rows are calculated comparison metrics, not published prices — how they are derived.
Benchmarks
These two models do not currently report scores on any of the same benchmark suites, so there is no like-for-like capability comparison to show. Rather than pad the page with one-sided numbers, the benchmark leaderboards list every score we do hold.
What each model is for
GPT-5
OpenAI · Frontier
OpenAI's 2025 flagship, unified reasoning + multimodal model with a 400K context. Replaces the GPT-4 line as the default ChatGPT and API model.
- Unified reasoning + chat
- 400K context
- Native vision
- Strong tool use
DeepSeek-V4-Flash
DeepSeek · Efficient
The public-beta release of DeepSeek V4 Flash, which supersedes the earlier preview with substantially stronger agentic behaviour; DeepSeek reports its agent scores beating the larger V4-Pro-Preview. Its defining feature is the price/capability ratio: a 1M-token context window at a fraction of frontier rates. The listed price is DeepSeek's cache-miss rate; cache hits bill lower.
- Very low cost for a 1M-context model
- Agentic task performance
- Long-context handling
- Cheaper cache-hit pricing
Frequently asked questions
Which is cheaper, GPT-5 or DeepSeek-V4-Flash?
On blended cost DeepSeek-V4-Flash undercuts GPT-5 by about 21.3×: $0.182 per million tokens versus $3.88. A single 100K-input, 10K-output job costs $0.017 on DeepSeek-V4-Flash against $0.225 on GPT-5. Blended cost weights input at 70% and output at 30%; price your own token split for an exact answer, since the cheaper model on a blended basis is not always cheaper for your workload.
Which has the larger context window, GPT-5 or DeepSeek-V4-Flash?
On context, DeepSeek-V4-Flash is the larger at 1,000,000 tokens versus 400,000. The context window caps everything in a single request: prompt, retrieved documents, conversation history and the model’s own output all share it.
Can I compare GPT-5 and DeepSeek-V4-Flash on my own numbers?
Yes. Open both in the side-by-side comparison tool to see every field at once, or use the token calculator to price your actual prompt and monthly request volume against each model. Both are free and need no sign-up.
Price it for your own workload
Related matchups
Terms used on this page
Prices and scores are recomputed on every deploy from the catalogue. Prices checked 12 August 2026.