vercel/next.js · error

A page's revalidate option must be seconds expressed as a na

Error message

A page's revalidate option must be seconds expressed as a natural number. Mixed numbers and strings cannot be used. Received '${JSON.stringify(data.revalidate)}' for ${req.url}

What it means

Error "A page's revalidate option must be seconds expressed as a natural number. Mixed numbers and strings cannot be used. Received '${JSON.stringify(data.revalidate)}' for ${req.url}" thrown in vercel/next.js.

Source

Thrown at packages/next/src/server/render.tsx:1032

                `\nTo only run getStaticProps at build-time and not revalidate at runtime, you can set \`revalidate\` to \`false\`!`
            )
          }

          revalidate = data.revalidate
        }
      } else if (data.revalidate === true) {
        // When enabled, revalidate after 1 second. This value is optimal for
        // the most up-to-date page possible, but without a 1-to-1
        // request-refresh ratio.
        revalidate = 1
      } else if (
        data.revalidate === false ||
        typeof data.revalidate === 'undefined'
      ) {
        // By default, we never revalidate.
        revalidate = false
      } else {
        throw new Error(
          `A page's revalidate option must be seconds expressed as a natural number. Mixed numbers and strings cannot be used. Received '${JSON.stringify(
            data.revalidate
          )}' for ${req.url}`
        )
      }
    } else {
      // By default, we never revalidate.
      revalidate = false
    }

    props.pageProps = Object.assign(
      {},
      props.pageProps,
      'props' in data ? data.props : undefined
    )

    // pass up cache control and props for export
    metadata.cacheControl = { revalidate, expire: undefined }

View on GitHub (pinned to 89d017eac4)

Solutions

1. Return `revalidate` as a single number (seconds) or `false`, e.g. `return { props: {}, revalidate: 60 }`.
2. Do not mix numbers and strings or use expressions that produce non-integer values.

When it happens

Trigger: Thrown at packages/next/src/server/render.tsx:1034 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of vercel/next.js@89d017eac4 (2026-08-19). Data as JSON: /api/errors/f1cce20331f1583c. Report an issue: GitHub.