GPT-5 vs OpenAI o3
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
GPT-5
70.7OpenAI · Aug 2025
OpenAI's August 2025 unified flagship that merged the GPT and o-series reasoning lines into one model with selectable effort.
OpenAI o3
68.9OpenAI · Apr 2025
OpenAI's dedicated 2025 reasoning model that pioneered thinking-with-images and agentic tool use within chain-of-thought.
The verdict
GPT-5 wins 5 of the 5 benchmarks these models share, against 0 for OpenAI o3. GPT-5 is about 1.0x cheaper per blended million tokens (3:1 input:output mix). GPT-5 also takes 400K of context versus 200K for OpenAI o3.
Benchmark head-to-head 5–0
Specs & pricing
| GPT-5 | OpenAI o3 | |
|---|---|---|
| modhub Index | 70.7 | 68.9 |
| Input price / 1M | $1.25 | $2 |
| Output price / 1M | $10 | $8 |
| Context window | 400K | 200K |
| Max output | 128K | 100K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Sep 2024 | May 2024 |
| Released | Aug 2025 | Apr 2025 |
| Example monthly cost* | $27.50 | $32.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, GPT-5 or OpenAI o3?
- GPT-5 wins 5 of the 5 benchmarks these models share, against 0 for OpenAI o3. GPT-5 is about 1.0x cheaper per blended million tokens (3:1 input:output mix). GPT-5 also takes 400K of context versus 200K for OpenAI o3.
- Which is cheaper, GPT-5 or OpenAI o3?
- GPT-5 costs $1.25/$10 per million input/output tokens, while OpenAI o3 costs $2/$8. For a typical workload of 10M input and 1.5M output tokens per month, that's $27.50 versus $32.00.
- Which model is better for coding, GPT-5 or OpenAI o3?
- On SWE-bench Verified — the standard agentic-coding benchmark — GPT-5 scores 74.9% versus 69.1% for OpenAI o3, making GPT-5 the stronger pick for coding agents.