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Models · gpt-5

GPT-5

Proprietary OpenAI · — · Proprietary

OpenAI's first unified model, fusing the fast GPT-series with the deeper o-series reasoning track behind a real-time router that picks per-turn. Launched August 7 2025 via livestream; immediately default in ChatGPT, available in API and on the GitHub Models Playground. Ships in main, mini, nano, thinking, and thinking-mini variants with low/medium/high/minimal effort settings.

Cost

$1.25 / Mtok input
$10.00 / Mtok output

OpenAI API · as of 2026-05-21

source ↗

Speed

72 tok/sec output
106012 ms TTFT

· as of 2026-05-21

source ↗

Architecture

tokens in Embedding vocab not disclosed × N layers Architecture not disclosed (proprietary or undocumented) Output projection tokens out
Schema-generated from data/models.yaml. Every label is auditable against the model's sources.

Specs

Architecture
unknown
Total params
not disclosed
Active params
not disclosed
Context window
not verified
Attention
unknown
Position encoding
unknown
Post-training
rlhf
OSI-approved
no
Data released
no
Training code
not released

Benchmarks

Each score carries the date it was published; we never infer or interpolate missing scores.

General reasoning

MMLU-Pro 87.1 as of 2026-05-21 source ↗
GPQA-Diamond 85.4 as of 2026-05-21 source ↗

Code

LiveCodeBench 84.6 as of 2026-05-21 source ↗

Math

MATH 99.4 as of 2026-05-21 source ↗
AIME 2024 95.7 as of 2026-05-21 source ↗

Available quantizations

None. The weights are not distributed, so there are no public quantizations.

Notable innovations

  • · Unified router across fast and reasoning paths
  • · Effort and verbosity controls in the API
  • · Native multimodal pretraining

Lineage

First OpenAI model to fuse the GPT and o-series tracks via a real-time router.

Derived from

OpenAI o3 2025-04-16

Derivatives

Sources