AI Models · Open-Source vs Paid

GPT-4o Paid vs Mistral Medium 3.5 Open

GPT-4o vs Mistral Medium 3.5 compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

GPT-4oPaidOpenAI
$2.5 /M input
$10 /M outputManaged API (no infra to run)
TypeProprietary
Context window128K tokens
MultimodalYes
Self-hostNo
Mistral Medium 3.5OpenMistral AI
$1.5 /M input
$7.5 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window262K tokens
MultimodalYes
Self-hostYes
Choose Mistral Medium 3.5 if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-4o if you want frontier capability through a managed API with zero infrastructure to run.

GPT-4o vs Mistral Medium 3.5 specs

SpecGPT-4oMistral Medium 3.5Winner
MakerOpenAIMistral AI–
TypeProprietaryOpen-weightMistral Medium 3.5
Context window128K tokens262K tokensMistral Medium 3.5
Input price$2.5/M$1.5/M · free self-hostMistral Medium 3.5
Output price$10/M$7.5/M · free self-hostMistral Medium 3.5
Vision / multimodalYesYes= Tie
Tool / function callingYesYes= Tie
Self-hostableNo (API only)YesMistral Medium 3.5
LicenseProprietaryApache 2.0Mistral Medium 3.5

Price gap & when to choose each

Choose GPT-4o if…
  • You want frontier performance through a managed API
  • You value reliability & ecosystem
  • You don't want to manage infrastructure
Choose Mistral Medium 3.5 if…
  • You want to self-host or run on your cloud
  • You need the longer 262K context window
  • You prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI

Feature comparison

CapabilityGPT-4oMistral Medium 3.5
Open weights (downloadable)✗✓
Self-hostable✗✓
Runs fully offline✗✓
Vision / multimodal✓✓
Tool / function calling✓✓
1M+ context window✗✗

Benchmarks: GPT-4o vs Mistral Medium 3.5

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

Mistral Medium 3.5 delivers 2.5× more intelligence per dollar.
GPT-4o
Mistral Medium 3.5
Intelligence index
8.4
14.2
Math index
6
–
GPQA
54.3%
74.8%
MMLU-Pro
74.8%
–
Humanity's Last Exam
2.4%
13.8%
Long Context Reasoning
49.3%
69.3%
LiveCodeBench
30.9%
–
MATH-500
75.9%
–
AIME
15%
–
AIME 2025
6%
–
IFBench
34.3%
68.8%
τ²-Bench
25.1%
94.2%
Terminal-Bench Hard
8.3%
33.3%
Coding index
–
46.9
SciCode
–
40.2%
τ-Bench Banking
–
15.1%
Terminal-Bench
–
50.6%
Speed
0 tok/s
174.8 tok/s
Latency
0s
0.61s
Intelligence per $
1.9
4.7

Benchmark data by Artificial Analysis.

How GPT-4o and Mistral Medium 3.5 score

🏆 Best value & openness: Mistral Medium 3.5 (4.6 vs 2.9 / 5)
CriterionGPT-4oMistral Medium 3.5
Cost-efficiency3.54.0
Context window3.54.0
Openness1.55.0
Self-hosting1.05.0
Multimodality5.05.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

GPT-4o Paid

OpenAI · Proprietary

GPT-4o ("o" for "omni") is OpenAI's latest AI model, supporting both text and image inputs with text outputs. It maintains the intelligence level of [GPT-4 Turbo](/models/openai/gpt-4-turbo) while being twice as...

Mistral Medium 3.5 Open

Mistral AI · Open-weight

Mistral Medium 3.5 is a dense 128B instruction-following model from Mistral AI. It supports text and image inputs with text output, and is designed for agentic workflows, coding, and complex...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
Mistral Large 4Mistral Medium 3.5 (batch)Mistral Small 4Mistral Large 3 2512Mistral Medium 3.1Mistral Medium 3Devstral 2 2512Mistral Small 3.1 24BMistral Small 3.2 24BMistral LargeMistral Large 2407Mistral Small 3SabaMinistral 3 14B 2512Mixtral 8x22B InstructMinistral 3 8B 2512Ministral 3 3B 2512UncensoredCodestral 2508Voxtral Small 24B 2507Mistral Nemo

Frequently asked questions

Is Mistral Medium 3.5 as good as GPT-4o?

Mistral Medium 3.5 is open-weight and competitive on many tasks, but GPT-4o may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run Mistral Medium 3.5 locally?

Yes. Mistral Medium 3.5 has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT-4o is API-only and cannot be self-hosted.

GPT-4o vs Mistral Medium 3.5 — which should I pick in 2026?

Choose Mistral Medium 3.5 if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-4o if you want frontier capability through a managed API with zero infrastructure to run.

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