GPT-5.6 Luna vs o3
GPT-5.6 Luna leads the LLM Stats Score 44.2 to 31.0. GPT-5.6 Luna is 7.8x cheaper per token.
OpenAI · OpenAI · Updated for 2026
Which is better?
GPT-5.6 Luna leads the overall LLM Stats Score 44.2 to 31.0, ranking #45 overall.
In the 4 individual benchmarks reported for both models, GPT-5.6 Luna wins 4; this is a narrower head-to-head signal than the composite indexes.
On price, GPT-5.6 Luna is roughly 7.8x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.6 Luna also accepts a larger context window (1,050,000 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-5.6 Luna
- overall performance matters — it scores 44.2 and ranks #45 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- you value its reported benchmark strengths — it wins 4 of 4 exact shared results
- cost matters — it's about 7.8x cheaper per token
- you process long inputs — it offers a 1,050,000 token context window
- you want the most recent training data — it shipped Jul 2026
Choose o3
- you want predictable pricing at $2.00/M input and $8.00/M output
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
45 reported for GPT-5.6 Luna · 22 for o3
GPT-5.6 Luna outperforms in 4 benchmarks (BrowseComp, FrontierMath, GPQA, MMMU-Pro), while o3 is better at 0 benchmarks.
GPT-5.6 Luna 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-5.6 Luna ($0.20/1M tokens) is 10.0x cheaper than o3 ($2.00/1M tokens).
For output processing, GPT-5.6 Luna ($1.20/1M tokens) is 6.7x cheaper than o3 ($8.00/1M tokens).
In conclusion, o3 is more expensive than GPT-5.6 Luna.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.6 Luna accepts 1,050,000 input tokens compared to o3's 200,000 tokens. GPT-5.6 Luna 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-5.6 Luna and o3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.6 Luna
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-5.6 Luna was released on 2026-07-09, while o3 was released on 2025-04-16.
GPT-5.6 Luna is 15 months newer than o3.
Jul 9, 2026
3 months ago
1.2yr newerApr 16, 2025
1.5 years ago
Knowledge Cutoff
When training data ends
GPT-5.6 Luna has a knowledge cutoff of 2026-02-16, while o3 has a cutoff of 2024-05-31.
GPT-5.6 Luna has more recent training data (up to 2026-02-16), making it potentially better informed about events through that date compared to o3 (2024-05-31).
Feb 2026
1.8 yr newerMay 2024
Provider Availability
GPT-5.6 Luna is available from OpenAI. o3 is available from OpenAI.
GPT-5.6 Luna
o3
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.6 Luna and o3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.6 Luna vs o3.