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.
Related: Claude themes · Gemini themes · How to customize Claude · How to change your Gemini background
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.
Disclosure
We build Chroma AI, one of the tools in this category. That is a conflict of interest, and you should read this page with it in mind. The checklist below is written so you can evaluate any option — including ours — against the same criteria, and several of the points count against tools like ours as often as for them.
How to evaluate a theming extension
- Scope of permissions. A theming tool needs to run on the chat sites it styles and nothing else. "All sites" access is broader than the job requires.
- Where settings are stored. Local browser storage means the tool works offline and has no account to leak. An account-based tool should explain clearly what that account is for.
- Update cadence. These sites redesign frequently and every redesign breaks styling. Check the last-updated date; a tool untouched for a year is likely already broken in places.
- Whether it touches conversation content. Restyling a page requires reading its structure. Reading, storing, or transmitting the text of your conversations is a different thing entirely, and the privacy disclosures should make that distinction explicit.
- Performance cost. Heavy blur effects and animated backgrounds are the usual culprits when an interface starts feeling sluggish. Try a theme for a full working session before deciding you like it.
- What happens when you uninstall. A well-behaved extension leaves nothing behind; the site returns to its default appearance immediately.
If none of the available options clear this bar for you, a user stylesheet you write yourself is a legitimate alternative — more maintenance, no third-party access at all.
Want the one that covers all three?
Free for ChatGPT, Claude and Gemini. Separate theme per site.
Get Chroma AI — Free