How to Install and Use Complexity (cplx.app) on Chrome or Firefox

Complexity is a browser extension that adds quality-of-life features to Perplexity.ai, and you install it the same way as any other extension: from the Chrome Web Store or Mozilla Add-ons. Once installed, it works automatically on Perplexity.ai — there is no separate app to launch or account to create. The sections below cover where to get it, what to expect after installation, and how to handle the most common snags.

Where to get Complexity

Complexity is distributed through two official browser extension stores, both linked from the cplx.app homepage:

Because the extension is published on Mozilla Add-ons, it is not Chrome-only. One user review on the site (Markus Weninger, Jul 2, 2024) notes they switched their default browser from Firefox to Brave specifically to use the extension — a reminder that Chromium-based browsers such as Brave, Edge, and others can generally install from the Chrome Web Store, while Firefox uses its own listing.

Installing it

1. Open the Chrome Web Store or Mozilla Add-ons listing from the links on cplx.app.
2. Click the install/add button for your browser.
3. Confirm the permissions prompt if one appears.
4. Open or reload Perplexity.ai.

Expected result: the Perplexity interface loads with Complexity's enhancements active. There is no setup wizard described on the site, so if nothing looks different, the first thing to check is whether the extension is enabled and whether the tab was reloaded after installation.

What you get after installation

Complexity's features are injected into the Perplexity.ai interface rather than living in a separate dashboard. According to the site, they include:

• On-the-fly model and focus mode switching — change your preferred model and focus mode even within an existing thread, instead of going back to the settings page.
• Spaces interaction from the homepage — start a new thread without navigating away from the homepage.
• Thread table of contents — jump around a long thread instead of scrolling.
• Sticky toolbar — keeps message actions (Rewrite, Edit, Copy with or without links, and similar) within reach.
• Custom Markdown block — no line wrap by default, plus syntax highlighting for languages Perplexity doesn't natively support.
• Experimental thread export — save an entire thread or individual messages as Markdown, with or without links.
• Custom theme — an ADHD-friendly color scheme out of the box, plus your own accent color, fonts, and more.
• Prompt Library — listed as in development, described as a system for creating, managing, and sharing prompts.

The practical takeaway: most of the value shows up as small changes inside the Perplexity UI. The model/focus selector and mid-thread switching are the features reviewers single out most — one review (Daily Focus, May 31, 2024) calls the model and collection selectors workflow-transforming and the mid-chat focus mode change "essential."

Common issues and how to approach them

Nothing changed on Perplexity.ai. Reload the tab, then confirm the extension is enabled in your browser's extensions page. If you installed from the Chrome Web Store in a non-Chrome Chromium browser, check that the browser allows store installs.

A feature behaves unexpectedly or a new Perplexity update breaks something. The site directs users to its Discord community to report issues and suggest new features. That is also the channel the developer uses for feedback — the same review above notes the developer is responsive to suggestions.

You want to know what's coming. The Prompt Library is marked "in development," and the site notes there are more features than fit on the page. Treat anything not listed as shipped as unconfirmed until it appears in the extension.

You're deciding whether it's worth installing. If you use Perplexity daily and find yourself repeatedly opening settings to switch models or focus modes, the extension targets exactly that friction. If you use Perplexity occasionally, the gains are smaller — the features are conveniences layered on top of the existing product, not a replacement for it.