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GPT-5 Mini vs GPT-5.5 Pro

Pricing per million tokens, context window, capabilities — pulled from each provider's public docs. All 2 are available via the same AIgateway OpenAI-compatible endpoint; flip the model string to switch.

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GPT-5 Mini
openai/gpt-5-mini
GPT-5.5 Pro
openai/gpt-5.5-pro
Provider
OpenAI
OpenAI
Family
GPT-5
GPT-5
Modality
text
text
Context window
128,000 tok
1,000,000 tok
Max output
16,384 tok
16,384 tok
Released
2026-05-22
2026-05-22
License
Proprietary
Proprietary
Input price
$0.250 /1M
$30.00 /1M
Output price
$2.00 /1M
$180.00 /1M
Tools
yes
yes
Streaming
yes
yes
Vision
yes
yes
JSON mode
yes
yes
Reasoning
yes
yes
Prompt caching
Batch API
Try it
Open in playground →
Open in playground →
GPT-5 Mini
openai/gpt-5-mini
Full spec →

GPT-5 Mini is the lightweight, low-cost variant of GPT-5, well suited to high-volume coding and reasoning tasks.

Strengths
  • General-purpose chat
  • Long context
  • Tool use
Use cases
ChatbotsContent generationAgentic workflows
GPT-5.5 Pro
openai/gpt-5.5-pro
Full spec →

GPT-5.5 pro uses OpenAI's Responses API with built-in tools, improved reasoning, and stateful context management.

Strengths
  • General-purpose chat
  • Long context
  • Tool use
Use cases
ChatbotsContent generationAgentic workflows

Compare with another

Claude Opus 5 vs GPT-5.5 Pro
anthropic/claude-opus-5 · openai/gpt-5.5-pro
Grok 4.5 vs GPT-5.5 Pro
xai/grok-4.5 · openai/gpt-5.5-pro
Kimi K3 vs GPT-5.5 Pro
moonshot/kimi-k3 · openai/gpt-5.5-pro
Gemini 3.6 Flash vs GPT-5.5 Pro
google/gemini-3.6-flash · openai/gpt-5.5-pro
GPT-5.6 Sol vs GPT-5.5 Pro
openai/gpt-5.6-sol · openai/gpt-5.5-pro
Claude Fable 5 vs GPT-5.5 Pro
anthropic/claude-fable-5 · openai/gpt-5.5-pro
DeepSeek V4 Pro vs GPT-5.5 Pro
deepseek/deepseek-v4-pro · openai/gpt-5.5-pro
Gemini 3.1 Pro vs GPT-5.5 Pro
google/gemini-3.1-pro · openai/gpt-5.5-pro
MiniMax M3 vs GPT-5.5 Pro
minimax/m3 · openai/gpt-5.5-pro
SWITCH BETWEEN THEM

One key, all 2, one line different.

from openai import OpenAI

client = OpenAI(
    base_url="https://api.aigateway.sh/v1",
    api_key="sk-aig-...",
)

# GPT-5 Mini
client.chat.completions.create(
    model="openai/gpt-5-mini",
    messages=[{"role":"user","content":"hello"}],
)

# GPT-5.5 Pro
client.chat.completions.create(
    model="openai/gpt-5.5-pro",
    messages=[{"role":"user","content":"hello"}],
)
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