GPT-5.3 Instant
speedOpenAI•Released on 2026-03-05
GPT-5.3 Instant is OpenAI's speed-optimized model designed for applications where latency matters as much as quality. It features a 26.8% reduction in hallucinations compared to GPT-5.2, an 'anti-cringe' tone overhaul that eliminates performative language patterns, and sub-800ms time-to-first-token latency. Available through the OpenAI API as gpt-5.3-chat and in ChatGPT Plus, Team, and Enterprise.
84
Overall Score
Core Specs
128K
Context Window
16K
Max Output
✗
Reasoning
✗
Open Source
Multimodal Support
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Scenario Scores
User Feedback Highlights
Based on community feedback. Hover to see original reviews.
+ Sub-800ms time-to-first-token latency+ Full function calling & structured outputs+ 26.8% fewer hallucinations than GPT-5.2− 128K context (smaller than GPT-5.4's 1M)− No reasoning mode+ Anti-cringe tone: natural, direct responses+ Affordable speed-tier pricing− 16K max output tokens− No computer use capability
Sentiment:👍 0%😐 0%👎 0%
Pros & Cons
Pros
- +Sub-800ms time-to-first-token latency
- +26.8% fewer hallucinations than GPT-5.2
- +Anti-cringe tone: natural, direct responses
- +Full function calling & structured outputs
- +Affordable speed-tier pricing
Cons
- −128K context (smaller than GPT-5.4's 1M)
- −No reasoning mode
- −No computer use capability
- −16K max output tokens
Reliability
Pricing
Input (per 1M tokens)$1.75
Output (per 1M tokens)$14.00
Subscription$20/month
Free trial available
Updated on 2026-03-12
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Compare with Others
Benchmarks
simpleQA93.9%
sweVerified64.7%
math50092.3%
mmluPro84.1%
mmmu73.8%
humanEval95.1%
gpqaDiamond61.4%