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Can't connect to Supabase from Vercel? The direct connection uses IPv6

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Source checked 6 Oct 2026 · Published 21 Oct 2026 · Last reviewed 21 Oct 2026 · By Ctrl+Z Therapy (how we test)

The short answer

All Supabase databases provide a direct connection string that maps to an IPv6 address. Supabase lists a few platforms that only accept IPv4 connections: Retool, Vercel, GitHub Actions and Render. So a direct connection that works from your laptop can fail from there. The fix is the shared pooler, which Supabase says is IPv4 on every plan.

What to do

  1. In the Supabase Dashboard, click Connect and choose Transaction pooler.
  2. Put that connection string in your host's environment variables, like on Vercel, and redeploy.
  3. Open your live app and check that it connects now.

Good to know

  • For serverless and edge functions, Supabase recommends the shared pooler in transaction mode anyway, because these environments open many short-lived connections.
  • Only reading and writing data through supabase-js? The Supabase client libraries are IPv4 compatible.
  • On Pro and above, you can also enable a dedicated IPv4 add-on.

Source

Checked on 6 Oct 2026. Prices, limits and settings change, so check the source before you rely on them.

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