Vellum: Animated Themes & Backgrounds for ChatGPT & Claude

100 handcrafted themes for ChatGPT & Claude with animated backgrounds, dark modes, and a 7-day free trial. No data collected.

=== DESCRIPTION === Vellum turns ChatGPT and Claude into something worth looking at. Most theme extensions just recolour the page. Vellum gives you 100 hand-crafted ANIMATED backgrounds — starfields that drift, koi gliding through water, a black hole pulling matter into its accretion disk, neon grids racing to the horizon. They move. Quietly, in the background, while you work. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 100 THEMES, ORGANISED ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Browse by category instead of endless scrolling: ★ Space ★ Nature ★ Weather ★ Fire ★ Retro ★ Minimal ★ Abstract ★ Ambient ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ WHY VELLUM ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✓ Genuinely animated — not static gradients ✓ Works on both ChatGPT and Claude ✓ 21 free themes, forever, no account needed ✓ Syncs across your devices ✓ One-click screenshots of your themed chat ✓ Dark-mode native — designed to be easy on the eyes ✓ No data collected. No tracking, no analytics, no accounts. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ FREE vs PRO ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 21 themes are free forever — no card, no sign-up. Pro unlocks all 100, including every animated background, plus new themes as they drop. Try everything free for 7 days. Cancel any time. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ PRIVACY ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Vellum collects nothing. No browsing history, no chat contents, no analytics, no account. Your themes are stored in your own browser and sync via your Google account. Vellum stores a local flag in your browser to track trial status; it is never transmitted. Vellum is an independent extension and is not affiliated with, endorsed by, or sponsored by OpenAI or Anthropic.