Duplicate named routes definition

Error message

Duplicate named routes definition: { name: "${name}", path: "${record.path}" }

What it means

Two route records define the same `name`. Only the first registration is kept in nameMap, so navigation by that name resolves to the first path, silently ignoring the later duplicate. The warning is skipped for alias-matched records (matchAs).

Solutions

Rename one of the routes so each name is unique
Deduplicate routes before registering (by name) when building routes dynamically
Use router.hasRoute / check nameMap before adding in Vue Router 4
If dynamic re-registration is intended, remove the old route first

Example fix

// before
[{ path: '/a', name: 'user' }, { path: '/b', name: 'user' }]
// after
[{ path: '/a', name: 'user-a' }, { path: '/b', name: 'user-b' }]

Defensive patterns

Strategy: validation

Validate before calling

function assertUniqueNames(routes) {
  const seen = new Set()
  for (const r of routes) {
    if (r.name) {
      if (seen.has(r.name)) throw new Error(`Duplicate route name: ${r.name}`)
      seen.add(r.name)
    }
  }
}
assertUniqueNames(routes)

Prevention

Enforce unique route names with a unit test over the route table
Namespace route names per module when merging route configs
Check existing names before dynamic registration

When it happens

Trigger: routes: [{ path: '/a', name: 'x' }, { path: '/b', name: 'x' }] — the second addRoute with name 'x' hits the existing nameMap entry; also common when addRoutes/addRoute is called repeatedly with overlapping configs.

Common situations: Copy-pasted route definitions; dynamically generated routes re-registered with the same names; merging route modules that reuse names.

Related errors

AI-assisted analysis of vuejs/vue-router@680ccc68c5 (2026-09-02). Data as JSON: /api/errors/c275136403a6a46b. Report an issue: GitHub.

Appendix: source

Thrown at src/create-route-map.js:184

        path: alias,
        children: route.children
      }
      addRouteRecord(
        pathList,
        pathMap,
        nameMap,
        aliasRoute,
        parent,
        record.path || '/' // matchAs
      )
    }
  }

  if (name) {
    if (!nameMap[name]) {
      nameMap[name] = record
    } else if (process.env.NODE_ENV !== 'production' && !matchAs) {
      warn(
        false,
        `Duplicate named routes definition: ` +
          `{ name: "${name}", path: "${record.path}" }`
      )
    }
  }
}

function compileRouteRegex (
  path: string,
  pathToRegexpOptions: PathToRegexpOptions
): RouteRegExp {
  const regex = Regexp(path, [], pathToRegexpOptions)
  if (process.env.NODE_ENV !== 'production') {
    const keys: any = Object.create(null)
    regex.keys.forEach(key => {
      warn(
        !keys[key.name],

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