GPT-3.5 Turbo vs GPT-4o
Head-to-head specifications
| Metric | GPT-3.5 Turbo | GPT-4o | Difference |
|---|---|---|---|
| MMLU (general capability) | 70.0% | 88.7% | -18.7% |
| Context window | 16K tokens | 128K tokens | — |
| Price (input / output per 1M) | $0.5 / $1.5 | $2.5 / $10 | — |
| Access | Proprietary API | Proprietary API | — |
- GPT-4o leads general capability (MMLU 88.7% vs 70.0%).
- GPT-4o offers the larger context window, useful for long documents and codebases.
Verdict: GPT-3.5 Turbo or GPT-4o?
GPT-3.5 Turbo advantages
- Input cost (+80%)
- Output cost (+85%)
GPT-4o advantages
- General capability (+21%)
- Context window (+88%)
Which should you choose?
- Choose the GPT-3.5 Turbo if you process large volumes of input and want the lowest cost.
- Choose the GPT-4o if you need the strongest reasoning and accuracy.
- Choose the GPT-3.5 Turbo if you generate a lot of output and want the lowest cost.
Value for money
GPT-3.5 Turbo offers more capability per dollar — a better value pick for high-volume use, delivering 4.93× the MMLU-per-cost of the alternative.
GPT-3.5 Turbo vs GPT-4o: which should you choose?
GPT-3.5 Turbo — OpenAI large language model (2023) with a 16K-token context window and an MMLU score of 70.0%.
GPT-4o — OpenAI large language model (2024) with a 128K-token context window and an MMLU score of 88.7%.
GPT-3.5 Turbo vs GPT-4o: GPT-4o scores higher on the MMLU benchmark. GPT-4o leads general capability (MMLU 88.7% vs 70.0%). GPT-4o offers the larger context window, useful for long documents and codebases.
Capability and reasoning
On MMLU — a 57-subject benchmark of general knowledge and reasoning — the GPT-4o scores 88.7% versus 70.0%. MMLU is a useful proxy for raw knowledge but does not capture instruction-following, coding, tool use, latency or safety, so treat it as one signal among several.
Context window
The GPT-4o handles up to 128K tokens per request, which sets how much documentation, transcript or code it can reason over at once — decisive for retrieval-augmented and long-document workflows.
Pricing and access
GPT-3.5 Turbo is proprietary api and GPT-4o is proprietary api. Proprietary models bill per token via API; open-weight models can be self-hosted, trading per-call cost for infrastructure you manage. For production, weigh throughput, rate limits and data-residency needs alongside headline price.
The verdict
Both are credible choices in the ai model comparison space; the specification table above lays out every metric so you can weigh the trade-offs that matter to you. Pick the one whose strengths line up with how you will actually use it.
Frequently asked questions
Is the GPT-3.5 Turbo better than the GPT-4o?
These two are closely matched — the right pick comes down to which specific strengths you value and the price you actually pay. GPT-4o leads general capability (MMLU 88.7% vs 70.0%).
What is the main difference between the GPT-3.5 Turbo and the GPT-4o?
GPT-4o leads general capability (MMLU 88.7% vs 70.0%). GPT-4o offers the larger context window, useful for long documents and codebases.
Which is better value?
GPT-3.5 Turbo offers more capability per dollar — a better value pick for high-volume use, delivering 4.93× the MMLU-per-cost of the alternative.
Which should I choose?
Choose the GPT-3.5 Turbo if you process large volumes of input and want the lowest cost. Choose the GPT-4o if you need the strongest reasoning and accuracy.
Methodology
Large language models are compared on the MMLU benchmark (a widely-cited 57-subject test of general knowledge and reasoning, reported as a percentage), maximum context window, and published API pricing per million input and output tokens. Open-weight models can also be self-hosted. Benchmarks capture only part of real-world quality, which also depends on tool use, latency, safety and task fit.