What to Look for When Hiring Technical SEO Companies

I have worked with more than a dozen technical SEO companies over the past decade, both as an in-house marketer and as a consultant on the agency side. Some engagements were smooth, developer-friendly, and actually fixed things. Others left me with a PDF full of screenshots and a bill I could not justify to my team. The difference usually came down to how the technical seo companies approached the audit itself and whether they understood that their real client was not me, but the developers who would read the report.

If you are comparing technical seo companies right now, you probably already know that a basic crawl and a list of missing meta descriptions will not move the needle. You need a partner who can surface the issues that keep Googlebot from crawling and indexing your important pages, and who can present those issues in a way that your engineering team will actually take seriously. Let me walk through the capabilities and red flags I have seen, and how you can evaluate whether a vendor truly understands technical SEO at the depth your site requires.

Start With the Crawl Setup

Every serious technical SEO engagement begins with a crawl. But not all crawls are equal. I have seen reports built entirely from a default Screaming Frog run, which misses JavaScript-rendered content, ignores mobile-specific markup, and treats every redirect as a simple status code without checking the redirect chain. A good technical SEO company will configure the crawler to match how Googlebot actually sees your site. They will use Screaming Frog or Sitebulb with JavaScript rendering enabled, set a custom user-agent string that matches Googlebot, and throttle the crawl rate to avoid hammering your server.

Sitebulb has become my preferred tool for this kind of work because it visualises crawl depth and internal link distribution in a way that Screaming Frog does not. But the tool matters less than the methodology. Ask the vendor how they handle JavaScript SEO during the crawl. If they cannot explain how they verify that Googlebot can access and render your React-based navigation or your lazy-loaded product images, that is a red flag. A crawl that ignores JavaScript SEO will miss half the issues on a modern site.

Indexation and the Tools That Reveal It

Crawl data tells you what is there. Indexation data tells you what Google actually keeps. The best technical SEO companies combine crawl output with data from Google Search Console and log file analysis to understand where Googlebot spends its time and where it stops. I once worked with a site that had 200,000 indexed URLs, but 80 percent of Googlebot's crawl budget went to parameterized faceted navigation pages. A standard crawl would never have shown that. Only log file analysis, paired with Google Search Console's coverage report, revealed the pattern.

When you evaluate a vendor, ask how they incorporate Google Search Console into their audit. Do they pull the performance report, the coverage report, and the URL inspection tool data? Do they cross-reference that with server logs? If they cannot talk about crawl budget in the context of your specific site architecture, they are probably running a checklist, not a real audit.

Prioritization That Speaks to Developers

Here is where most technical seo companies fall short. They produce an SEO audit report that lists 150 issues sorted by severity, but severity is defined by SEO impact alone. The problem is that a developer looking at that list sees no context about engineering effort. A canonical tag misconfiguration might be a high-severity SEO issue, but it takes five minutes to fix. A fundamental site architecture problem might be a medium-severity issue that requires two weeks of refactoring. If the report does not distinguish between those two, the developer will work through the quick wins and ignore the rest.

The best technical SEO companies I have worked with provide a prioritised remediation plan that includes an effort estimate, a risk assessment, and a suggested order of implementation. They use HTTP status codes and redirect chain data to show exactly where the fix goes. They include before-and-after examples from Google PageSpeed Insights and Core Web Vitals reports to demonstrate why each fix matters. When a developer sees that a specific render-blocking resource is causing a 200-millisecond delay on the Largest Contentful Paint metric, they know exactly what to change and why it matters.

Structured Data and Entity Signals

Structured data is one of those areas where a little knowledge can be dangerous. I have seen audits that simply check whether you have JSON-LD on your homepage and call it done. But real technical SEO requires understanding which schema types map to your content, whether your structured data passes Google's validation, and whether it actually triggers a rich result. A good vendor will use Semrush or Ahrefs to identify which of your pages already have structured data and which are missing the markup that your competitors have. They will also check for common errors like missing required fields or mismatched @type values.

Moz's tools can help with link analysis and domain authority comparisons, but for structured data specifically, I prefer Ahrefs' site audit because it surfaces schema errors alongside other technical issues. The key is that the vendor should not treat structured data as a standalone checklist item. It should be woven into the broader crawl analysis, with the same level of effort estimation and prioritization as every other issue.

XML Sitemaps, Robots.txt, and Canonical Tags

These three elements form the foundation of crawl and indexation control. Yet I have seen audits that simply report whether the XML sitemap exists and whether the robots.txt file is accessible. A real technical SEO audit will verify that the XML sitemap includes only canonical URLs, that it is under the 50,000-URL and 50MB limits, that it is referenced in the robots.txt, and that it is submitted to Google Search Console. It will also check whether the sitemap includes noindexed pages or redirects, which wastes crawl budget.

The canonical tag analysis should go beyond checking for presence. The vendor should crawl your site and flag every page where the canonical tag points to a different domain, a non-200 URL, or a page that itself has a canonical tag pointing elsewhere. That kind of loop is shockingly common, and it can confuse Googlebot into ignoring your preferred URL entirely. A vendor who understands canonical tags at this level will also check for conflicts between the canonical tag and the hreflang attribute if you run a multilingual site.

Log File Analysis and the Indexing API

Log file analysis is the most underutilized technique in technical SEO. It is also the one that separates the good technical SEO companies from the rest. By examining your server logs, you can see exactly which URLs Googlebot requests, how often, and what HTTP status codes it receives. You can identify crawl waste, detect pages that Googlebot cannot reach because of robots.txt blocks, and spot patterns like Googlebot hitting a redirect chain that ends at a 404.

I have also started seeing the indexing API used more frequently, especially for large e-commerce sites where real-time indexing of new product pages matters. If your site has thousands of pages that change daily, a vendor should be able to discuss whether the indexing API is appropriate for your use case and how it interacts with your existing XML sitemap strategy. This is not a common topic, but if a vendor brings it up unprompted, it signals deep technical understanding.

How to Make the Final Decision

When you are down to two or three technical seo companies, ask each one to produce a mini audit of a single section of your site. Give them the same five URLs and a week to deliver a sample report. Compare the output. Does it include crawl data from Screaming Frog or Sitebulb? Does it reference Core Web Vitals metrics from Google PageSpeed Insights? Does it use Semrush or Ahrefs to benchmark your structured data against competitors? Does it include a prioritised remediation plan with effort estimates?

The sample report will tell you more than any sales deck. A vendor who delivers generic recommendations does not understand your site. A vendor who takes the time to understand your technology stack, your crawl budget, and your developer workflow is worth the investment. That is the kind of partner who will help you fix the issues that actually impact your rankings, rather than just producing a document that gathers dust.