## **🧭 Overview**

Site Audit crawls your website the way a search engine or browser would, then scores what it finds. Two things cause most customer questions: the **user agent** setting, and **score differences** between projects or between crawls. This article explains both and helps you pick the right settings.

## **🤖 What Is a User Agent?**

A user agent is a label a crawler sends to your website to say who it is. Your server can respond differently depending on that label. For example, it might serve a mobile version of a page to a mobile browser, or block an unfamiliar crawler.

The user agent you choose in Site Audit controls how your site sees the crawler. That can change which pages load, which content appears, and which issues are reported.

## **📱 Why Is My Project Set to Chrome Mobile?**

If you see a project set to a Chrome mobile user agent and you don't remember changing it, this is usually not a mistake. Common reasons include:

- **It was the default or suggested option** when the project was created.
- **Mobile-first reasoning:** Google primarily uses the mobile version of a site for indexing, so a mobile user agent shows you something close to what Google evaluates.
- **A teammate with access** to the project or account may have changed it.
- **Different projects can have different settings.** Each project keeps its own crawl configuration, so one project's setting does not carry over to another.

You can review the current setting at any time in the project's Site Audit settings. The exact option names may vary slightly as the platform is updated.

## **✅ Which User Agent Should I Use?**

There is no single right answer for every site, but this guidance works for most customers:

- **Search Atlas user agent:** A good choice if you want a clean, clearly identified crawl. It's also easier to allow-list if your site has a firewall or security tool, because you can recognize it in your server logs.
- **Chrome mobile:** A good choice if you want to see your site as a mobile visitor sees it. This is useful if mobile pages differ from desktop pages, or if you care about mobile-first indexing.
- **Chrome desktop:** Useful if your desktop and mobile versions differ and you want to check the desktop experience specifically.

**Rule of thumb:** If your site is responsive (the same pages for mobile and desktop), either the Search Atlas or Chrome mobile option will give very similar results. If your site blocks or limits crawlers, start with the Search Atlas user agent and allow-list it, or switch to a browser-style option.

## **🛠️ How to Change the User Agent**

1. Open the project you want to update.
2. Go to **Site Audit** and open the crawl or audit settings for that project.
3. Find the **User Agent** option and select the one you want.
4. Save your changes.
5. Start a new crawl so the new setting is applied.

Changing the setting does not rewrite past results. You need to run a fresh crawl to see how the new setting affects your score and issues list.

## **📊 Why Do Scores Differ Between Projects or Crawls?**

A Site Audit score reflects what the crawler found during that specific crawl. If two scores don't match, one of these factors is usually the cause:

- **Different user agents:** A site may serve different content, redirects, or errors to a mobile crawler than to a desktop or custom crawler.
- **Different crawl limits:** If one project crawls more pages than another, the score is based on a different set of pages.
- **Blocked or throttled requests:** Firewalls, security plugins, or rate limits can block some pages. The crawler then records errors or skips pages, which changes the score.
- **Site changes between crawls:** New pages, deleted pages, redirects, or fixed issues all shift the results.
- **Robots rules and exclusions:** Pages blocked by robots.txt or excluded in your settings are not scored the same way.
- **Temporary server issues:** Slow responses or short outages during a crawl can create errors that do not appear in the next one.

## **🔄 How to Compare Scores Fairly**

1. Make sure both projects use the **same user agent**.
2. Check that the **page limit and crawl settings** match.
3. Confirm that no security tool is **blocking the crawler** on either site.
4. Run a **new crawl** on both projects at around the same time.
5. Compare the issue lists, not just the overall score, to see exactly what changed.

Scores from other SEO tools may also differ from Search Atlas. Every tool crawls differently, checks a different set of issues, and weights them differently. Use each tool's score to track your own progress over time rather than to compare tools directly.

## **🚧 If the Crawl Seems Blocked**

Signs that your site may be blocking the crawler include a very low page count, many access errors (such as 403 or 429), or a crawl that stops early. To fix this:

- Ask your developer or host to **allow-list** the Search Atlas user agent.
- Check security plugins and CDN or firewall rules for bot-blocking settings.
- Try a browser-style user agent as a test, then run a new crawl.

## **💡 Best Practices**

- Review the user agent on each project when you set it up, instead of relying on the default.
- Keep settings consistent across projects you plan to compare.
- Re-crawl after any change to settings or after major site updates.
- Track the trend in your score over time, since small shifts between crawls are normal.

## **💬 Need More Help?**

If you need further assistance, open the chat widget in the bottom-right corner of the platform and type **human teammate** to be instantly connected with a member of our team.