Describe the bug
I ran into an issue with {@html} in SvelteKit 3, that didn't happen using SvelteKit 2.
I noticed that trying to render invalid html via {@html} results in a 500 server error.
Two examples I found:
<p>Html without closing tag<p>Valid html</p> but rendered inside anothter <p>.
The logs don't generate any errors, which made it hard to debug.
I've created a repo and deployed it to Vercel here.
Reproduction
Repository: https://github.com/hankolsen/sveltekit3-html-issue
Running in Vercel: https://sveltekit3-html-issue.vercel.app/
When the page is server side rendered it results in a 500 error for at least the two examples available. Client side navigation works, so either load the page directly or reload it do force server side rendering.
Logs
System Info
System:
OS: macOS 15.7.7
CPU: (12) arm64 Apple M2 Max
Memory: 89.27 MB / 32.00 GB
Shell: 5.9 - /bin/zsh
Binaries:
Node: 24.15.0 - /Users/hank/.nvm/versions/node/v24.15.0/bin/node
npm: 11.12.1 - /Users/hank/.nvm/versions/node/v24.15.0/bin/npm
pnpm: 12.3.4 - /Users/hank/Library/pnpm/bin/pnpm
bun: 1.4.0 - /opt/homebrew/bin/bun
Deno: 2.9.6 - /opt/homebrew/bin/deno
Browsers:
Brave Browser: 153.1.95.101
Chrome: 153.0.8010.50
Firefox: 155.0
Safari: 26.6.1
npmPackages:
@sveltejs/adapter-auto: ^8.0.0-next.3 => 8.0.0-next.4
@sveltejs/adapter-vercel: ^7.0.0-next.9 => 7.0.0-next.9
@sveltejs/kit: ^3.0.0-next.0 => 3.0.0-next.27
@sveltejs/vite-plugin-svelte: ^7.2.0 => 7.3.0
svelte: ^5.56.7 => 5.57.0
vite: ^8.1.5 => 8.3.0Severity
blocking an upgrade
Additional Information
I noticed the issue when I pulled in content from a CMS that I don't control.
So, this is a blocking an upgrade to SvelteKit 3 at the moment.
Describe the bug
I ran into an issue with
{@html}in SvelteKit 3, that didn't happen using SvelteKit 2.I noticed that trying to render invalid html via
{@html}results in a 500 server error.Two examples I found:
<p>Html without closing tag<p>Valid html</p>but rendered inside anothter<p>.The logs don't generate any errors, which made it hard to debug.
I've created a repo and deployed it to Vercel here.
Reproduction
Repository: https://github.com/hankolsen/sveltekit3-html-issue
Running in Vercel: https://sveltekit3-html-issue.vercel.app/
When the page is server side rendered it results in a 500 error for at least the two examples available. Client side navigation works, so either load the page directly or reload it do force server side rendering.
Logs
System Info
System: OS: macOS 15.7.7 CPU: (12) arm64 Apple M2 Max Memory: 89.27 MB / 32.00 GB Shell: 5.9 - /bin/zsh Binaries: Node: 24.15.0 - /Users/hank/.nvm/versions/node/v24.15.0/bin/node npm: 11.12.1 - /Users/hank/.nvm/versions/node/v24.15.0/bin/npm pnpm: 12.3.4 - /Users/hank/Library/pnpm/bin/pnpm bun: 1.4.0 - /opt/homebrew/bin/bun Deno: 2.9.6 - /opt/homebrew/bin/deno Browsers: Brave Browser: 153.1.95.101 Chrome: 153.0.8010.50 Firefox: 155.0 Safari: 26.6.1 npmPackages: @sveltejs/adapter-auto: ^8.0.0-next.3 => 8.0.0-next.4 @sveltejs/adapter-vercel: ^7.0.0-next.9 => 7.0.0-next.9 @sveltejs/kit: ^3.0.0-next.0 => 3.0.0-next.27 @sveltejs/vite-plugin-svelte: ^7.2.0 => 7.3.0 svelte: ^5.56.7 => 5.57.0 vite: ^8.1.5 => 8.3.0Severity
blocking an upgrade
Additional Information
I noticed the issue when I pulled in content from a CMS that I don't control.
So, this is a blocking an upgrade to SvelteKit 3 at the moment.