SVELTE 5+

Drop-in svelte-check. 60× faster type-checks.

Rust parser, parallel transforms, tsgo type-checking — built for CI and AI coding agents.

$npm install -D svelte-check-rs
[ BENCH ]
svelte-check
svelte-check-rs
=> faster
> methodology
tool
hyperfine 1.20 · n=5 per scenario (1 warmup)
target
SvelteKit monorepo · 531 .svelte · 1,573 .ts/.js · ~415k LOC
cold
rm -rf .svelte-kit + tool cache before each run
warm
caches preserved, no file changes
iterative
single isolated src/lib/*.ts edit before each run
vs
svelte-check 4.4.8 · svelte-check-rs 0.9.14
env
Apple M4 Max · 48 GB · macOS 26.5 · svelte 5.55 · kit 2.60 · tsgo 7.0.0-dev.20260521

# context

svelte-check is built on Language Server Protocol — optimized for IDEs with persistent connections and incremental updates. Great for autocomplete. Slow for one-shot CLI checks.

svelte-check-rs is batch-first. No LSP. Parallel diagnostics for pipelines and agents.

[ for ]
  • AI coding agents (Claude Code, Codex)
  • CI/CD pipelines
  • Pre-commit hooks
  • Watch-mode iteration
[ not for ]
  • In-editor diagnostics
  • Autocomplete / IntelliSense
  • Hover documentation
  • Go-to-definition

Keep using the Svelte VS Code extension for IDE features. Still on Svelte 4? Stick with svelte-check.

# cli

[ core ]
--workspace <path>
Project root
--tsconfig <path>
TypeScript config
--output <fmt>
human | json | machine
--watch
Re-check on file change
[ diagnostics ]
--threshold
error | warning
--fail-on-warnings
Exit 1 on warnings
--ignore <glob>
Skip matching files
--skip-tsgo
Skip type-checking
[ debug ]
--timings
Timing breakdown
--timings-format
text | json
--debug-paths
Resolved binaries
--emit-ts
Print transformed TS
[ tooling ]
--tsgo-version
Installed tsgo version
--bun-version
Installed bun version
--bun-update
Update bun to latest
--bun-update=<ver>
Install specific version