Vercel turns tracing on by default for new Next.js projects

Vercel now turns tracing on by default for new Next.js projects, no setup required. The change applies to projects created on or after 5 November, once a deployment builds with Next.js 16.5 or later and includes at least one Node.js function. Static exports and Edge-only apps don’t qualify.

Once eligible, Vercel adds a sampling rule that traces 100% of requests across every environment, and injects @vercel/otel into the build so traces include Next.js framework spans, routes and rendering, on top of the infrastructure spans every request already gets. It doesn’t touch your package.json or lockfile to do it. If your project already has its own instrumentation.ts, or already depends on @opentelemetry/api 1.10 or later, you keep infrastructure spans but lose the automatic framework spans unless you wire up @vercel/otel yourself.

# eligible: new project, Next.js 16.5+, at least one Node.js function
# not eligible: vercel deploy --prebuilt, static export, Edge-only

Why it matters: this is billed like any other tracing usage, counted in span units, so a default of tracing every single request can run up usage you didn’t ask for. Hobby gets 1 million span units a month before tracing pauses team-wide; Pro and Enterprise pay $0.50 per million. Check Settings → Tracing on any new project and lower the sampling rate, or turn it off, before it surprises you on the invoice.

The caveat: you can’t just disable the default rule, you have to remove all sampling rules to stop billing, and if you later want tracing back you add a rule yourself rather than re-enabling the default.