AI Models · Open-Source vs Paid

Mistral Medium 3.5 Open vs GPT-5.6 Terra Paid

Mistral Medium 3.5 vs GPT-5.6 Terra 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.

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-5.6 Terra if you want frontier capability through a managed API with zero infrastructure to run.

Mistral Medium 3.5 vs GPT-5.6 Terra specs

SpecMistral Medium 3.5GPT-5.6 Terra
MakerMistral AIOpenAI
TypeOpen-weightProprietary
Context window262K tokens1.1M tokens
Input price$1.5/M · free self-host$1.25/M
Output price$7.5/M · free self-host$7.5/M
Vision / multimodalYesYes
Tool / function callingYesYes
Self-hostableYesNo (API only)
LicenseApache 2.0Proprietary

Feature comparison

CapabilityMistral Medium 3.5GPT-5.6 Terra
Open weights (downloadable)
Self-hostable
Runs fully offline
Vision / multimodal
Tool / function calling
1M+ context window

Benchmarks: Mistral Medium 3.5 vs GPT-5.6 Terra

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

Mistral Medium 3.5
GPT-5.6 Terra
Intelligence index
29.9
55
Coding index
46.9
76.7
GPQA
74.8%
92.5%
Humanity's Last Exam
12.8%
41.8%
Long Context Reasoning
61%
74%
SciCode
39.6%
53.9%
IFBench
68.8%
71.2%
τ²-Bench
94.2%
86.3%
τ-Bench Banking
14.4%
31.8%
Terminal-Bench
50.6%
88%
Terminal-Bench Hard
33.3%
57.6%
Speed
59.8 tok/s
136.5 tok/s
Latency
0.77s
106.97s
Intelligence per $
10
9.8

Benchmark data by Artificial Analysis.

How Mistral Medium 3.5 and GPT-5.6 Terra score

🏆 Best value & openness: Mistral Medium 3.5 (4.6 vs 3.3 / 5)
CriterionMistral Medium 3.5GPT-5.6 Terra
Cost-efficiency4.04.0
Context window4.05.0
Openness5.01.5
Self-hosting5.01.0
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

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...

GPT-5.6 Terra Paid

OpenAI · Proprietary

GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic...

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 Small 4Devstral 2 2512Mistral Large 3 2512Mistral Medium 3.1Mistral Small 3.1 24BMistral Medium 3Ministral 3 14B 2512Mistral Small 3.2 24BMinistral 3 8B 2512Mistral LargeMistral Large 2407Mistral Small 3SabaMinistral 3 3B 2512Mixtral 8x22B InstructCodestral 2508UncensoredVoxtral Small 24B 2507Mistral Nemo

Frequently asked questions

Is Mistral Medium 3.5 as good as GPT-5.6 Terra?

Mistral Medium 3.5 is open-weight and competitive on many tasks, but GPT-5.6 Terra 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-5.6 Terra is API-only and cannot be self-hosted.

Mistral Medium 3.5 vs GPT-5.6 Terra — 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-5.6 Terra if you want frontier capability through a managed API with zero infrastructure to run.

People also compare

Explore more open-source AI

Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.

Open the leaderboard →