User Agent Parser Template

What it does

Starts with yours

On load the route reads the visitor's own User-Agent header, so a deployed copy shows each person their browser.

Browser, OS and device

Names the browser and version, operating system, device vendor and model, and rendering engine.

Spots bots

Tells crawlers like Googlebot apart from real browsers, with its own look for bots.

Out-of-date check

Shows how many versions behind the browser is, and whether its OS version still gets updates.

Keeps your key private

The browser only talks to your own API route, which holds the key, caches answers for a day and rate-limits visitors.

How it works

The route: use the pasted string or the visitor's own header, then call User Agent Parser.

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export async function POST(request: Request) {
  const body = await request.json().catch(() => ({}));
  const ua = body?.mine ? str(request.headers.get('user-agent'), 1000) : str(body?.ua, 1000);
  if (!ua) return fail('Paste a user agent string to parse');

  const key = `ua:${createHash('sha1').update(ua).digest('hex')}`;
  const hit = fromCache(key, TTL_MS);
  if (hit) return Response.json(hit);

  const blocked = guard(request);
  if (blocked) return blocked;

  return respond(async () => {
    const data = await callApi('useragentparser', { json: { ua } });
    toCache(key, data);
    return data;
  });
}

See the whole file on GitHub →

Deploy it

1. Get a free API key

   The free plan includes 200 credits a month, no card needed. Create your key.

2. Deploy it

   Click Deploy to Vercel. Vercel copies the repo to your GitHub account and asks for APIVERVE_API_KEY: paste your key there.

3. Open your app

   Vercel builds it and gives you a live URL, usually in about a minute. Every push to the repo redeploys it.

Try the User Agent Parser API — the call this template makes

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{
  "status": "ok",
  "error": null,
  "data": {
    "ua": "Mozilla/5.0 (Windows NT 6.4) AppleWebKit/537.36.0 (KHTML, like Gecko) Chrome/60.0.0.0 Safari/537.36.0",
    "browser": {
      "name": "Chrome",
      "version": "60.0.0.0",
      "major": "60"
    },
    "engine": {
      "name": "Blink",
      "version": "60.0.0.0"
    },
    "os": {
      "name": "Windows",
      "version": "10"
    },
    "device": {},
    "cpu": {},
    "isMobile": false,
    "isBot": false,
    "deviceType": "desktop",
    "clientType": "browser",
    "library": null,
    "isSuspicious": false,
    "suspiciousReasons": [],
    "osVersionFrozen": true,
    "versionCheck": {
      "browserFamily": "Chrome",
      "latestVersion": "156",
      "majorsBehind": 95,
      "isOutdated": true,
      "osEndOfLife": null
    },
    "summary": "Chrome 60 on Windows 10"
  }
}