DeepSeek
Open-source frontier reasoning that just leveled up with V4 — pay per token
Why we recommend DeepSeek
Why we recommend DeepSeek
DeepSeek is a relatively young Chinese AI lab that in August 2026 launched its next-gen V4 series (deepseek-v4-flash, deepseek-v4-pro, deepseek-v4-flash-vision-exp). Three things stand out:
Open source + commercial friendly — DeepSeek ships model weights, training details, and inference code under a permissive MIT license. You can use, modify, fine-tune, and self-host the model commercially without paying anyone — a sharp contrast to "open weights, no commercial use" competitors.
Strong reasoning — The new DeepSeek-V4-Pro pushes well past prior generations on math, code, logic, and Agent benchmarks, and natively supports the Responses API and Codex. DeepSeek-V4-Flash-Vision-Exp additionally accepts image input for multimodal coding.
Cost-controlled — DeepSeek bills on a peak/off-peak schedule: Monday–Friday UTC 01–04 and 06–10 are peak (double price), all other hours off-peak at half. Cache-hit input is cheaper. For V4-Flash, peak per 1M tokens is $0.014 input (cache hit) / $0.44 (cache miss) and $1.32 output, halved off-peak; V4-Pro is $0.044 / $1.32 / $3.96 (peak). Overall still far below closed-source frontier models — great for high-volume workloads.
In practice, platform.deepseek.com is reliably reachable from inside China, the API is 100% OpenAI-compatible (existing code can switch with one baseURL change), and top-ups work via WeChat / Alipay without a credit-card gate.
Billing model note — DeepSeek does not offer a fixed Coding Plan subscription; it's pure pay-per-token. The "plans" above are illustrative pricing rows for the V4 series (deepseek-v4-flash / deepseek-v4-pro / v4-flash-vision-exp), not tiers you can subscribe to; the previous-gen deepseek-chat / deepseek-reasoner are now offline. Peak/off-peak pricing took effect 2026-08-23 (Monday–Friday UTC 01–04, 06–10 peak; off-peak half). Real billing is on the platform.deepseek.com console.
If your project is high-volume, budget-sensitive, and needs frontier reasoning, DeepSeek-V4 is one of the strongest cost-per-quality plays on the market right now.