Temperature Is the Most Underrated Model Parameter for Frontend Work

temperature: 1.0

That is not a minor config tweak. That is the difference between a portfolio site that looks hand-crafted and one that looks like a Bootstrap template.

The parameter nobody talks about

You're evaluating a new model for frontend work. You run it through your standard prompts: build a landing page, add some animations, make it look polished. The results come back flat. Functional, but visually generic. You move on to the next model.

But the problem might not be the model. It might be the temperature setting you never changed from the default.

For GLM 4.6, the difference is stark. At temperature 0.6, you get clean, predictable output: the component renders, the logic works, the CSS is sensible. At temperature 1.0, you get particle effects, hover animations, gradient backgrounds, and design choices that look like someone actually thought about aesthetics.

Same model. Same prompt. Different parameter. Fundamentally different results.

The split personality

"Temperature matters a lot for this model. If you want good-looking stuff, temperature one. If you want stuff to be like functional API stuff, you probably want lower temperature like 0.6ish."

GosuCoder, After Hours S01E01

This is not a spectrum where higher temperature means "more creative but less reliable." It is a mode switch. The model at 0.6 is solving a different problem than the model at 1.0.

At lower temperature, the model optimizes for correctness and predictability. It produces code that works, follows conventions, and avoids risks. This is exactly what you want for API integrations, data transformations, and business logic.

At higher temperature, the model takes aesthetic risks. It adds visual flourishes that a conservative prompt would never produce. The tradeoff: you need to review the output more carefully, because "creative" sometimes means "unexpected."

"So this is temperature one... Now it looks like our website."

GosuCoder, After Hours S01E01

The practical setup

The solution is not "always use high temperature" or "always use low temperature." The solution is separate API profiles for separate jobs.

Design profile (temperature 1.0):

• Landing pages
• Portfolio sites
• Marketing components
• Anything where visual polish matters

Functional profile (temperature 0.6):

• API integrations
• Form validation
• Data processing
• Anything where predictability matters

In Roo Code, you can create API configuration profiles that store these settings. Switch profiles based on the task, not mid-conversation. The model behaves differently depending on which profile is active, so treat them as different tools for different jobs.

How Roo Code enables task-specific temperature control

Roo Code's BYOK (Bring Your Own Key) architecture means you configure model parameters directly in your API provider profiles-temperature, top_p, and other settings are yours to control. Because Roo Code closes the loop by running code, executing tests, and iterating on results, the temperature setting affects the entire agentic cycle: a design-focused profile at temperature 1.0 generates visually sophisticated components that Roo Code can then validate by actually rendering and testing them.

The key advantage: you can switch between a conservative functional profile and an expressive design profile without leaving your editor, and Roo Code will iterate on the output regardless of which mode you choose.

Old approach vs. new approach

The evaluation trap

Here is where teams waste time: they evaluate a model once, with default settings, and conclude it is not good at frontend work.

But model evaluation without parameter tuning is incomplete. A model that looks mediocre at temperature 0.6 might produce excellent results at temperature 1.0. The inverse is also true: a model that looks "creative" at high temperature might be unreliable for production API code.

If you are comparing models for frontend work, run the same prompt at multiple temperature settings. The "best" model depends on what you are optimizing for, and that changes based on the task.

Why this matters for your workflow

For engineers doing frontend work, temperature is the variable that determines whether you spend an hour tweaking CSS to make generated output look polished, or whether the first render already has the visual sophistication you need.

The time cost is real. If every generated component needs manual aesthetic fixes, you are doing the work the model should have done. If the model produces visually interesting output on the first pass, you are reviewing and shipping, not redesigning.

The shift: treat temperature as a task-specific parameter, not a set-and-forget default. Create profiles. Switch based on the job. Stop evaluating models at one temperature and concluding they cannot do design work.