Claude Haiku 4.5 vs GPT-5: Detailed Comparison

Choosing between Claude Haiku 4.5 (Anthropic) and GPT-5 (OpenAI) comes down to three things: per-token pricing, context window, and which capability matters most for your workload. Claude Haiku 4.5 costs $1.00/M input vs $1.25/M for GPT-5; context windows are 200K vs 400K tokens. Detailed breakdown below.

Side-by-side specs

SpecClaude Haiku 4.5GPT-5
ProviderAnthropicOpenAI
Released2025-10-012025-08-07
Input price $1.00/M $1.25/M
Output price $5.00/M $10.00/M
Cached input $0.1000/M $0.1300/M
Context window 200K 400K
Max output 16K 128K
Modalities text image text image
Tokenizer claude-3 o200k_base

Capability matrix

CapabilityClaude Haiku 4.5GPT-5
function calling Yes Yes
json mode Yes Yes
vision Yes Yes
streaming Yes Yes
tool use Yes No
reasoning No Yes

Benchmark comparison

Higher is better for all benchmarks shown.

BenchmarkCategoryClaude Haiku 4.5GPT-5Δ
MMLU-Pro general 88.4
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)Claude Haiku 4.5GPT-5Cheaper by
Standard chat (1K / 500) $0.003500 $0.006250 Claude Haiku 4.5 by $0.002750
RAG (4K / 500) $0.006500 $0.010000 Claude Haiku 4.5 by $0.003500
Long doc (20K / 1K) $0.025000 $0.035000 Claude Haiku 4.5 by $0.010000
Very long context (100K / 2K) $0.107500 $0.140000 Claude Haiku 4.5 by $0.032500

When to choose Claude Haiku 4.5 over GPT-5

  • Per-token input cost is 20% lower — meaningful for high-volume workloads.
  • Supports tool use — GPT-5 does not.

When to choose GPT-5 over Claude Haiku 4.5

  • Larger context window (400K vs 200K).
  • Supports reasoning — Claude Haiku 4.5 does not.

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