Svelte 1 End of Life
Support dates and upgrade guidance — rebuilt from live data.
End of Life
Svelte 1 reached end of life on 19 Apr 2018. It no longer receives security fixes.
3,034 days without security patches
Recommended action: upgrade to Svelte 5. Check your versionnpm list svelte
Support timeline
Official dates from the Svelte release process.
| Milestone | Date | Status |
|---|---|---|
| Initial release | 29 Nov 2016 | — |
| End of life | 19 Apr 2018 | 8.3 years ago |
| Latest release | 1.64.1 · 18 Apr 2018 | final |
Where to go from 1
Recommended target: Svelte 5.
The newest actively supported branch is Svelte 5 (latest release 5.56.8).
Frequently asked questions
Is Svelte 1 still safe to use?
Svelte 1 reached end of life on 19 Apr 2018, 3,034 days ago, and is no longer covered by standard support. Running it means no guaranteed security fixes.
Can I still download Svelte 1?
Yes — the final release (1.64.1) generally remains available from vendor archives and OS package mirrors, but installing it means running software with known, unpatched vulnerabilities.
What should I upgrade Svelte 1 to?
Upgrade to Svelte 5, the newest actively supported branch.