GPT-5.3-Codex vs Mistral Large 3: which is better for agents?

GPT-5.3-Codex scores higher on output quality (6.8/10 vs 3.4/10), while Mistral Large 3 is the cheaper option. GPT-5.3-Codex is best for existing Codex setups on an API key that still pin GPT-5.3-Codex; Mistral Large 3 is best for general open-weight text work where EU provenance matters. Live community votes on this page show what people actually prefer.

Is GPT-5.3-Codex cheaper than Mistral Large 3?

Mistral Large 3 is cheaper: roughly $0.80 vs $5.42 per 1M tokens (blended). GPT-5.3-Codex: $1.75 in · $14 out / 1M tokens. Mistral Large 3: $0.50 in · $1.50 out / 1M tokens.

Can I switch between GPT-5.3-Codex and Mistral Large 3 in the same agent?

Yes. Model-agnostic agents (Cline, Aider, OpenClaw, Hermes Agent, Kilo Code, OpenCode) let you swap models per task. Many people route hard tasks to the stronger model and routine work to the cheaper one.

GPT-5.3-Codex vs Mistral Large 3: Which Is Better? (2026)

Community vote

Pick a winner in each dimension. You can change your vote any time. 1 vote cast so far.

Output Quality

Correctness and depth of what it produces

100%1 vote0%

Agentic Ability

Tool calls, instruction-following, and multi-step tasks

Speed

Tokens per second and time-to-first-token

Value for Money

How much capability you get per dollar

Reliability

Consistent results: fewer refusals, loops and format breaks

Specs and pricing side by side

Spec

GPT-5.3-Codex

Mistral Large 3

Maker

OpenAI

Mistral

Blended price / 1M

$5.42

$0.80

Input / output

$1.75 in · $14 out / 1M tokens

$0.50 in · $1.50 out / 1M tokens

Context window

400K

262K

Open weights

Yes

Tool use

Yes

Reasoning

Yes

Output Quality

6.8

3.4

Agentic Ability

5.1

4.4

Speed

8.0

7.0

Value for Money

5.0

5.5

Reliability

8.4

Pricing and capabilities synced from the OpenRouter catalogue. Scores are editorial (0–10).

Verdict: GPT-5.3-Codex or Mistral Large 3?

Updated 2026-10-17

Choose GPT-5.3-Codex if you want existing Codex setups on an API key that still pin GPT-5.3-Codex. Choose Mistral Large 3 if you want general open-weight text work where EU provenance matters.

In our editorial scoring, GPT-5.3-Codex leads in 3 of five dimensions (output quality, agentic ability and speed), while Mistral Large 3 leads in 1. On price, GPT-5.3-Codex runs about $5.42 per 1M tokens (blended) and is proprietary; Mistral Large 3 is about $0.80 and open-weight.

Across 1 community votes on this matchup, GPT-5.3-Codex currently leads in 1 of five dimensions. Cast your own vote above to move the needle.

Where GPT-5.3-Codex falls short

Deprecated in Codex with ChatGPT sign-in
GPT-6.1 Sol scores far higher for about 20% more per request ($0.067 vs $0.055)

Full GPT-5.3-Codex breakdown →

Where Mistral Large 3 falls short

Not suited to agentic coding (0% in Artificial Analysis's Terminal-Bench 4.0 run)
262K context, smaller than 11.7% of the coding-agent requests we measured

Full Mistral Large 3 breakdown →

Current Claude, GPT, Gemini and open models run on Standard Compute

Standard Compute

Current frontier models Claude Fable 5.1 · GPT-6 Astra