DeepSeek-V3 vs GPT-5: Detailed Comparison

Choosing between DeepSeek-V3 (DeepSeek) and GPT-5 (OpenAI) comes down to three things: per-token pricing, context window, and which capability matters most for your workload. DeepSeek-V3 costs $0.27/M input vs $1.25/M for GPT-5; context windows are 128K vs 400K tokens. Detailed breakdown below.

Side-by-side specs

SpecDeepSeek-V3GPT-5
ProviderDeepSeekOpenAI
Released2024-12-262025-08-07
Input price $0.27/M $1.25/M
Output price $1.10/M $10.00/M
Cached input $0.0700/M $0.1300/M
Context window 128K 400K
Max output 8K 128K
Modalities text text image
Tokenizer deepseek o200k_base

Capability matrix

CapabilityDeepSeek-V3GPT-5
function calling Yes Yes
json mode Yes Yes
streaming Yes Yes
vision No Yes
reasoning No Yes

Benchmark comparison

Higher is better for all benchmarks shown.

BenchmarkCategoryDeepSeek-V3GPT-5Δ
MMLU-Pro general 75.9 88.4 -12.5
HumanEval coding 82.6
GPQA Diamond reasoning 85.7
SWE-bench Verified coding 74.9
AIME 2025 math 94.6

Per-call cost on typical workloads

Workload (in/out tokens)DeepSeek-V3GPT-5Cheaper by
Standard chat (1K / 500) $0.000820 $0.006250 DeepSeek-V3 by $0.005430
RAG (4K / 500) $0.001630 $0.010000 DeepSeek-V3 by $0.008370
Long doc (20K / 1K) $0.006500 $0.035000 DeepSeek-V3 by $0.028500
Very long context (100K / 2K) $0.028650 $0.140000 DeepSeek-V3 by $0.111350

When to choose DeepSeek-V3 over GPT-5

  • Per-token input cost is 78% lower — meaningful for high-volume workloads.

When to choose GPT-5 over DeepSeek-V3

  • Larger context window (400K vs 128K).
  • Supports vision — DeepSeek-V3 does not.
  • Supports reasoning — DeepSeek-V3 does not.

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