webext-smoothgpt

Features

Instant speed recovery — eliminates the jitter and input lag that builds up in long ChatGPT threads, regardless of message count.
CSS-containment only — applies content-visibility: auto to off-screen turns; no nodes are removed or detached from the DOM.
Nothing breaks — Ctrl+F, text selection, code-block copy buttons, and ChatGPT's own React reconciliation all keep working normally.
Fully local, zero telemetry — the extension makes no network calls beyond the page itself and collects no data.
Live stats popup — a toolbar popup shows how many turns are virtualised vs. rendered live, with a one-click on/off toggle.
Activates only when needed — containment engages past 30 turns so short conversations are left entirely untouched.
Minimal & private — no account, no telemetry; permissions are limited to ChatGPT content-script access plus activeTab and storage for the popup toggle.

ChatGPT keeps every message turn live in the DOM. In long threads this produces thousands of nodes that the browser must re-layout on each new token. SmoothGPT applies CSS containment (content-visibility: auto + contain-intrinsic-size) to turns outside the viewport, telling the browser it can skip their rendering until they are scrolled into view. The nodes remain in the DOM — Ctrl+F, text selection, code-block copy buttons, and ChatGPT's own React reconciliation all continue to work normally.

Containment is only engaged once a conversation exceeds 30 turns. The currently-streaming turn and the last turn are always exempted to preserve auto-scroll-to-bottom behaviour. A MutationObserver on the conversation container keeps containment applied as new turns arrive and survives SPA chat switches.

Install

Firefox Add-ons (AMO): link will appear after first submission.

To load temporarily for development, see Development below.

Development

npm install
npm run dev        # launches Firefox Nightly with the extension loaded

Content-script and icon changes hot-reload automatically under web-ext run — no manual reload needed.

To load without Firefox Nightly: open about:debugging → This Firefox → Load Temporary Add-on and point to manifest.json. The extension is removed on browser restart.

Command	Description
`npm run dev`	Launch Firefox Nightly with the extension hot-loaded
`npm run lint`	Validate manifest and source against AMO rules
`npm run build`	Package into `web-ext-artifacts/`

Publishing

First submission — run bash publish.sh. This builds the package, opens the AMO Developer Hub in your browser, and reveals the web-ext-artifacts/ folder. Upload the .zip manually and complete the listing (description, screenshots, review queue). The very first submission cannot be automated.

Subsequent releases — bump, tag, and push:

npm version patch   # or minor / major
git push --follow-tags

npm version syncs the new version into manifest.json automatically (via the version lifecycle hook). CI picks up the v* tag, signs the package, and uploads it to AMO.

CI setup (one time) — before the first CI-driven release, add two secrets to the GitHub repo:

gh secret set MOZILLA_ADDONS_JWT_ISSUER
gh secret set MOZILLA_ADDONS_JWT_SECRET

Retrieve both values from addons.mozilla.org/en-US/developers/addon/api/key/.

Permissions

https://chatgpt.com/* and https://chat.openai.com/* — content-script injection; required to read and modify the conversation DOM.
activeTab — lets the toolbar popup read live stats from the ChatGPT tab you have open, only when you click it.
storage — persists the popup's on/off toggle locally.

No data leaves the browser.

Licence