> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fiddler.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# New Fiddler UI (Preview) — Quick Start

> An optional, self-service preview of Fiddler's redesigned interface for GenAI applications and ML models: how to open it, find your way around, and share feedback.

An **optional preview** of a redesigned Fiddler interface
for both your GenAI applications and your ML models.
It uses your existing account and data —
only the layout and navigation are new, and you can switch back anytime.

## Try It (and Switch Back)

* **Open it:** add `preview.` to the front of your usual Fiddler address —
  for example, `preview.your-company.cloud.fiddler.ai` — and sign in as usual.
* **Switch back:** remove `preview.` from the address.
  (There's no in-app toggle — you just edit the URL.)

## Find Your Way Around

The **left sidebar** replaces the old top bar (light and dark themes available)
and has two parts:

* **Top — your selected application or model.**
  Pick one with the selector at the top of the sidebar,
  and its own pages appear right below it.
  For a GenAI application, these include Overview,
  **Explorer**, and Evaluator Rules.
  For an ML model, these include Overview, Dashboard, Schema, and Baselines.
  They stay put as you work, so you move between them without going back to a list.
  *This is the biggest change — and the biggest click-saver.*
* **Below — Workspace.**
  The org-wide areas: Projects, Applications, Dashboards, Charts, Alerts, and more.
  Depending on your organization, Workspace can also include **Mission Control**
  (a cross-project overview for leadership, formerly "Executive Dashboard")
  and a **Predictive Models** list.

> [!NOTE]
>
> The items you see depend on your organization's settings and your permissions,
> so your sidebar may differ from the screenshots on this page.

![The redesigned Fiddler left sidebar with an application selected: the application's own pages on top, and the org-wide Workspace areas below](https://mintcdn.com/fiddlerai/G09wC1jSL7g36xKd/images/new-ui-preview-sidebar.png?fit=max\&auto=format\&n=G09wC1jSL7g36xKd\&q=85\&s=558975f246440a6b1cb97b883a161572)

![The Mission Control page in the redesigned Fiddler UI on its GenAI view, showing app and trace totals, evaluator scores, and span traffic and token usage charts](https://mintlify.s3.us-west-1.amazonaws.com/fiddlerai/images/new-ui-preview-mission-control.png)

## Monitoring ML Models

* **Open a model:** go to **Projects**, open a project, and select the model.
  If your organization has it turned on,
  the **Predictive Models** list under **Workspace** shows all your models in one place.
* **Investigate a change:** open a monitoring chart and click any data point.
  A **Root Cause Analysis** panel opens below the chart,
  with **Events**, **Analyze**, **Data Drift**, and **Data Integrity** tabs.
* **Add a model:** open an ML project and select **Add Model**.

![The redesigned Fiddler sidebar with an ML model selected, next to the model's Overview page showing its columns, baselines, segments, and custom metrics](https://mintlify.s3.us-west-1.amazonaws.com/fiddlerai/images/new-ui-preview-ml-model-overview.png)

![The Predictive Models list in the redesigned Fiddler UI, showing each model's onboarding date, column count, description, and project](https://mintlify.s3.us-west-1.amazonaws.com/fiddlerai/images/new-ui-preview-predictive-models.png)

![A Feature Drift chart for an ML model with the Root Cause Analysis panel open below it on the Data Drift tab](https://mintlify.s3.us-west-1.amazonaws.com/fiddlerai/images/new-ui-preview-ml-root-cause.png)

## Settings

**Settings** has four groups: **Organization**, **Access Control**, **Configuration**, and **Integrations**.
API keys are under **Settings → Credentials**.

## What's Not in the Preview Yet

For these, use your current Fiddler (remove `preview.` from the address):

* **Saved views:** Bookmarks
* **Setting up ML models:** draft models
* **Viewing ML models:** a model's Environments tab
* **GenAI applications:** the Enrichments tab

**Old links:** most links from your current Fiddler open the same page in the preview.
Some old links can't point to an exact page,
so they open a general page instead (such as the **Charts** or **Applications** list)
or a "Page not found" screen.
If that happens, look for the feature from there.
If you can't find it, it isn't in the preview yet.

> [!TIP]
>
> Not sure whether something's available? Ask your Customer Success Manager.

## Tell Us What You Think

Your feedback shapes the final release —
share it with your Fiddler Customer Success Manager.

***

*Optional preview — features and layout may change; the product name is not final.*