What is the best ChatGPT theme extension?

It depends on what you need. StylerGPT is the most established, with roughly 10,000 users and a large library of themes plus productivity tools like chat folders and PDF export, but it only works on ChatGPT. GPThemes is free and excellent for layout and typography — widescreen, chat width, font controls — but it does not support background images. Chroma AI is the only one of the three that also themes Claude and Google Gemini, and it focuses on background images and GIFs with glass blur, though it is much newer and has far fewer users.

Is there a theme extension that works on Claude and Gemini, not just ChatGPT?

Chroma AI supports ChatGPT, Claude and Google Gemini, and keeps a separate theme for each site. StylerGPT and GPThemes are ChatGPT-only. Most Claude and Gemini theming options are either userstyles, single-purpose extensions, or VS Code themes rather than full customization extensions.

Which ChatGPT theme extension supports background images and GIFs?

StylerGPT and Chroma AI both let you set a background image. GPThemes does not — it changes accent colors, layout and typography only. Chroma AI additionally supports animated GIF backgrounds with adjustable blur, opacity and a color overlay so text stays readable.

Are ChatGPT theme extensions free?

GPThemes is fully free with optional donations. StylerGPT is freemium with a 7-day trial for its Power features. Chroma AI is freemium: color presets, background images, blur and layout controls are free, while unlimited uploads, custom fonts and gallery publishing are Pro.

Do theme extensions read my ChatGPT conversations?

A theming extension does not need to. Chroma AI changes appearance on the client side only and never reads, stores or transmits conversation content. Before installing any extension, check its Chrome Web Store privacy disclosure and the permissions it requests — an extension that only restyles pages should not need access to sites beyond the AI chat pages it themes.

Comparison · Updated August 2026

Best ChatGPT theme extensions in 2026

Three extensions worth considering, compared on numbers you can verify yourself — user counts, ratings, which AI sites each one actually works on, and whether it can do background images. We make one of them, so we have said plainly where the other two are the better choice.

The short answer

If you only use ChatGPT and want the biggest, most proven option — StylerGPT. Roughly 10,000 users, 289 ratings at 4.8, a large theme and background library, plus chat folders, bulk delete and PDF export.

If you want a free, lightweight way to fix ChatGPT's layout — GPThemes. Widescreen mode, chat width, fonts and accent colors, rated 4.9 by 69 people, no payment at all. It does not do background images.

If you use Claude or Gemini as well as ChatGPT — Chroma AI, ours. It is the only one of the three that themes all three sites and keeps a separate look for each. It is also by far the newest and smallest, so weigh that.

Side by side

	StylerGPT	GPThemes	Chroma AI
Users (Chrome)	~10,000	~5,000	~97
Rating	4.8 (289)	4.9 (69)	5.0 (1)
ChatGPT	Yes	Yes	Yes
Claude	No	No	Yes
Google Gemini	No	No	Yes
Background images	Yes	No	Yes
Animated GIF background	Not advertised	No	Yes
Layout / widescreen	Yes	Yes	Yes
Custom fonts	~100 fonts	Yes	Yes (Pro)
Productivity tools	Folders, bulk actions, PDF export, prompt manager	None	None
Community theme sharing	Curated library only	No	User-uploaded gallery
Price	Freemium, 7-day trial	Free (donations)	Freemium
Size	5.25 MiB	—	17.9 MiB
Also on Edge	Yes	Chrome / Firefox	Yes

Figures read from each extension's Chrome Web Store listing on 10 August 2026. Chrome reports user counts in rounded bands, so treat them as approximate.

When each one is the right pick

StylerGPT — the safe default for ChatGPT-only users

It has the deepest library and the longest track record of the three, and it is not really a theming extension any more: chat folders, bulk archive and delete, export to PDF or Markdown, and a prompt manager sit alongside the themes. If ChatGPT is the only AI you use and you want one extension to do everything, this is the one to install. Reviews do note that a lot of it sits behind a subscription.

GPThemes — the best free option, if you don't need wallpapers

It solves the complaint most people actually have about ChatGPT, which is that the chat column is too narrow on a wide monitor. Widescreen, adjustable chat and composer width, line height, fonts, and an AMOLED black mode, all free with no account. The trade-off is explicit: no background images at all. If what you want is a wallpaper, this is not the extension.

Chroma AI — the only one that also covers Claude and Gemini

We built it because the other options stop at ChatGPT. It themes ChatGPT, Claude and Gemini, and each site keeps its own settings, which also makes tabs easier to tell apart at a glance. Backgrounds take any image or GIF, with blur, opacity and a color overlay so text stays readable over a busy picture, and there is a gallery where users publish themes others can apply in one click.

Where we are behind: we launched recently and have around 97 users and one rating, against StylerGPT's 289 ratings. We have no productivity tools — no folders, no export. And at 17.9 MiB we are the heaviest of the three, because wallpapers ship with the extension. If you only use ChatGPT and want a proven, feature-dense tool, StylerGPT is the more sensible choice today.

What about Claude and Gemini specifically?

This is where the market thins out sharply. Search for a Claude theme extension and most of what comes back is either a VS Code color theme, a userstyles.org stylesheet, a Firefox-only add-on, or a small single-purpose extension. Gemini is similar. Neither StylerGPT nor GPThemes runs on either site.

If you work across two or three assistants, that gap matters more than theme count. Giving each site a different background is the fastest way to stop opening the wrong tab, and it is the reason we kept settings separate per platform instead of applying one global theme.

How to judge any of these before installing

Check which sites it can touch

On the Chrome Web Store listing, look at the permissions. A theming extension should only ask for the AI chat sites it themes. If it wants access to every site you visit, ask why.

Read the privacy disclosure

Every listing has a Privacy section stating what the developer collects. Restyling a page does not require reading your conversations, so that line should be clear.

Look at the update date

ChatGPT, Claude and Gemini change their interfaces often. An extension last updated a year ago will likely be broken in places.

Ignore theme counts

"1000+ themes" usually counts colour and background combinations. What matters is whether you can use your own image and whether the text stays readable on top of it.

More on this: Chrome extension permissions explained

Frequently asked

Can I use two of these at once?

Technically yes, but they will fight over the same elements and the result is usually broken styling. Pick one, and disable the other rather than leaving both installed.

Do these work on the ChatGPT desktop app?

No. Browser extensions cannot reach a desktop application, so all three only work on the website. See Can you theme the ChatGPT desktop app?

Do they work on Edge, Brave or Opera?

All three are Chromium browsers, so Chrome extensions generally install and run on them. StylerGPT and Chroma AI are also listed directly on Microsoft Edge Add-ons. See Using Chroma AI on Edge, Brave and Opera

Will a theme slow ChatGPT down?

A colour theme costs essentially nothing. Heavy blur over an animated GIF background is the expensive combination, because the blur is recalculated every frame — which is why we drop blur on animated backgrounds while you scroll.

Want the one that covers all three?

Free for ChatGPT, Claude and Gemini. Separate theme per site.

Get Chroma AI — Free