GPT-5 nano vs o3
o3 leads the LLM Stats Score 30.8 to 19.1. GPT-5 nano is 25.5x cheaper per token.
OpenAI · OpenAI · Updated for 2026
Which is better?
o3 leads the overall LLM Stats Score 30.8 to 19.1, ranking #135 overall.
In the 4 individual benchmarks reported for both models, o3 wins 4; this is a narrower head-to-head signal than the composite indexes.
On price, GPT-5 nano is roughly 25.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5 nano also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-5 nano
- cost matters — it's about 25.5x cheaper per token
- you process long inputs — it offers a 400,000 token context window
- you want the most recent training data — it shipped Aug 2025
Choose o3
- overall performance matters — it scores 30.8 and ranks #135 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 4 of 4 exact shared results
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
5 reported for GPT-5 nano · 22 for o3
GPT-5 nano outperforms in 0 benchmarks, while o3 is better at 4 benchmarks (AIME 2025, FrontierMath, GPQA, Humanity's Last Exam).
o3 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5 nano ($0.05/1M tokens) is 40.0x cheaper than o3 ($2.00/1M tokens).
For output processing, GPT-5 nano ($0.40/1M tokens) is 20.0x cheaper than o3 ($8.00/1M tokens).
In conclusion, o3 is more expensive than GPT-5 nano.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5 nano accepts 400,000 input tokens compared to o3's 200,000 tokens. GPT-5 nano can generate longer responses up to 128,000 tokens, while o3 is limited to 100,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5 nano and o3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5 nano
o3
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-5 nano was released on 2025-08-07, while o3 was released on 2025-04-16.
GPT-5 nano is 4 months newer than o3.
Aug 7, 2025
1.2 years ago
3mo newerApr 16, 2025
1.5 years ago
Knowledge Cutoff
When training data ends
GPT-5 nano has a knowledge cutoff of 2024-05-30, while o3 has a cutoff of 2024-05-31.
o3 has more recent training data (up to 2024-05-31), making it potentially better informed about events through that date compared to GPT-5 nano (2024-05-30).
May 2024
May 2024
Provider Availability
GPT-5 nano is available from OpenAI. o3 is available from OpenAI.
GPT-5 nano
o3
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5 nano and o3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5 nano vs o3.