DeepSeek-R1 vs GPT-5 Nano: Detailed Comparison

Choosing between DeepSeek-R1 (DeepSeek) and GPT-5 Nano (OpenAI) comes down to three things: per-token pricing, context window, and which capability matters most for your workload. DeepSeek-R1 costs $0.55/M input vs $0.05/M for GPT-5 Nano; context windows are 128K vs 400K tokens. Detailed breakdown below.

Side-by-side specs

SpecDeepSeek-R1GPT-5 Nano
ProviderDeepSeekOpenAI
Released2025-01-202025-08-07
Input price $0.55/M $0.05/M
Output price $2.19/M $0.40/M
Cached input $0.1400/M $0.0050/M
Context window 128K 400K
Max output 32K 64K
Modalities text text
Tokenizer deepseek o200k_base

Capability matrix

CapabilityDeepSeek-R1GPT-5 Nano
json mode Yes Yes
streaming Yes Yes
reasoning Yes No
function calling No Yes

Benchmark comparison

Higher is better for all benchmarks shown.

BenchmarkCategoryDeepSeek-R1GPT-5 NanoΔ
GPQA Diamond reasoning 71.5
MATH math 97.3
AIME 2025 math 79.8

Per-call cost on typical workloads

Workload (in/out tokens)DeepSeek-R1GPT-5 NanoCheaper by
Standard chat (1K / 500) $0.001645 $0.000250 GPT-5 Nano by $0.001395
RAG (4K / 500) $0.003295 $0.000400 GPT-5 Nano by $0.002895
Long doc (20K / 1K) $0.013190 $0.001400 GPT-5 Nano by $0.011790
Very long context (100K / 2K) $0.058285 $0.005600 GPT-5 Nano by $0.052685

When to choose DeepSeek-R1 over GPT-5 Nano

  • Supports reasoning — GPT-5 Nano does not.

When to choose GPT-5 Nano over DeepSeek-R1

  • Per-token input cost is 91% lower than DeepSeek-R1.
  • Larger context window (400K vs 128K).
  • Supports function calling — DeepSeek-R1 does not.

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