Server Side Rendered (SSR) fallback routes with Gatsby

The unauthorized and rum-fueled treasure hunts in the sharky waters around the Gatsby islands Conference Buddy edition is back.

And on yesterday's stream helping Mirjam source conference data from Supabase, we briefly touched on fallback routes.

Screengrab of the intro

What are fallback routes?

It's a way to render pages for data that Gatsby does not yet sourced.

In Mirjam's case with Conference Buddy there will be a period between a user submits a conference and a fresh build picks up the conference for static generation.

In that interim time, we can rely on fallback routes using either CSR (Client Side Rendering) or SSR (Server Side Rendering).

I was not sure if SSR fallback route would be allowed, so I spun up a contrived demo using SSG (Static Site Generation) for sourced YouTube videos and SSR for non-sourced YouTube videos.

The Gatsby docs does not mention SSR for fallback routes, but it builds and serves locally on my machine. However I must admit I have not yet tested deployment...

SSG Page Code

// src/pages/yt/{}.js

import React from "react";
import { graphql } from "gatsby";

import VideoLayout from "../../components/video-layout";

const SSGVideoPage = ({ data }) => {
  return <VideoLayout {} />;

export default SSGVideoPage;

export const query = graphql`
  query ($id: String) {
    youTubeEmbed(id: { eq: $id }) {

Fallback SSR Page Code

// src/pages/yt/[youTubeId].js

import React from "react";

import { fetchEmbed } from "../../services/oembed";
import VideoLayout from "../../components/video-layout";
import NotFoundPage from "../404";

const SSRVideoPage = ({ serverData }) => {
  if (serverData) {
    return <VideoLayout {...serverData} />;
  } else {
    return <NotFoundPage />;

export default SSRVideoPage;

export async function getServerData({ params }) {
  console.log("SERVER SIDE RENDERING Page for ", params.youTubeId);

  const embedData = await fetchEmbed(params.youTubeId, console);

  return {
    props: embedData,


  • Gatsby's official documentation on Fallback Routes
  • The contrived example on CodeSandbox (CodeSandbox is a little buggy with Gatsby so give it some time/reloads if its messing up...)

Have you ever used fallback routes in a real-world project?

All the best,
Queen Raae

PS: Godt Nytt År (Happy New Year) 🎇

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