tailwindlabs/tailwindcss · error · Error

No configuration file found for ${highlight(relative(start))

Error message

No configuration file found for ${highlight(relative(start))}. Please provide a path to the Tailwind CSS v3 config file via the ${highlight('--config')} option.

What it means

`detectConfigPath` searches a list of default v3 config filenames (`tailwind.config.js`, `.cjs`, `.mjs`, `.ts`) walking up parent directories from `start` to `end`. If none is accessible via `fs.access`, the upgrade cannot locate the v3 config to migrate and throws, directing the user to pass `--config`.

Source

Thrown at packages/@tailwindcss-upgrade/src/codemods/template/prepare-config.ts:108

  './tailwind.config.js',
  './tailwind.config.cjs',
  './tailwind.config.mjs',
  './tailwind.config.ts',
  './tailwind.config.cts',
  './tailwind.config.mts',
]
export async function detectConfigPath(start: string, end: string = start) {
  for (let base of parentPaths(start, end)) {
    for (let file of DEFAULT_CONFIG_FILES) {
      let fullPath = path.resolve(base, file)
      try {
        await fs.access(fullPath)
        return fullPath
      } catch {}
    }
  }

  throw new Error(
    `No configuration file found for ${highlight(relative(start))}. Please provide a path to the Tailwind CSS v3 config file via the ${highlight('--config')} option.`,
  )
}

// Yields all parent paths from `from` to `to` (inclusive on both ends)
function* parentPaths(from: string, to: string = from) {
  let fromAbsolute = path.resolve(from)
  let toAbsolute = path.resolve(to)

  if (!fromAbsolute.startsWith(toAbsolute)) {
    throw new Error(`The path ${from} is not a parent of ${to}`)
  }

  if (fromAbsolute === toAbsolute) {
    yield fromAbsolute
    return
  }

View on GitHub (pinned to 16e94cbf7f)

Solutions

1. Pass the explicit path: `npx @tailwindcss/upgrade --config ./path/to/tailwind.config.js`.
2. Rename/create a config file using a default name in the project root.
3. Run the upgrade from the directory containing the v3 config.

Example fix

# before
npx @tailwindcss/upgrade

# after
npx @tailwindcss/upgrade --config ./tw.config.js

import { accessSync } from 'node:fs'
import path from 'node:path'
const DEFAULTS = ['tailwind.config.js','tailwind.config.cjs','tailwind.config.mjs','tailwind.config.ts']
function findV3Config(start: string, end = start) {
  for (const base of parentDirs(start, end)) {
    for (const f of DEFAULTS) {
      try { accessSync(path.resolve(base, f)); return path.resolve(base, f) } catch {}
    }
  }
  throw new Error('No v3 config found; pass --config <path>')
}

When it happens

Trigger: Running `@tailwindcss/upgrade` in a project with no `tailwind.config.*` file anywhere up the tree, or where the config has a non-default name. prepare-config.ts:108 throws after the `parentPaths`/`DEFAULT_CONFIG_FILES` loops complete without a hit.

Common situations: Projects that use a non-standard config filename (`tw.config.js`), config-in-JS without a file, or running the upgrade from the wrong directory.

Related errors

• Cannot find any CSS files that reference Tailwind CSS. Befor
• Unsupported content value: ${pattern}
• You have one or more stylesheets that are imported into a ut
• Could not find the Tailwind CSS v3 `prefix` configuration in
• Tailwind CSS is not installed

AI-assisted analysis of tailwindlabs/tailwindcss@16e94cbf7f (2026-08-12). Data as JSON: /api/errors/2ebcb77d5d01d570. Report an issue: GitHub.