Technical SEO: 8 essential checks

It can be hard to turn an agency's site audit into a request for your development team. The report says technical SEO needs improvement, but does not say what to fix or what counts as a fix.

A request with four columns (item, verification method, pass criteria, and source document) gives the developer a work ticket they can use. The passing standards in the checklist are drawn from the Google Search Central and web.dev official documentation.

1. An eight-item checklist for your development team

With these four columns, the table becomes a work request: what to check, how to check it, what counts as passing, and the source. PION delivers site audit findings in this format. The first three items are "Googlebot is not blocked," "The page works," and "The page has indexable content," which the Google Search technical requirements (updated December 18, 2025) list as the minimum conditions for being eligible for indexing.

Three representative pages are enough for this check. Choose your home page, your flagship service page, and one recent post, then mark them off in order.

1. Fetch /robots.txt and copy the User-agent groups for items 1 and 8 next to the table.
2. Disable JavaScript in your browser settings and reload the three pages. If the title, body, and internal links remain intact, item 4 passes.
3. Fetch the same address with curl and search for one body sentence. If there is no result, item 4 fails.
4. Mark items 2, 3, and 5 using Search Console URL Inspection, item 6 using the menu link addresses, and item 7 using the PageSpeed Insights results.
5. Pull out only the failing items and hand them to your development team. The pass criteria define when the work is complete; the source document explains where those criteria come from.

2. Indexing conditions for pages rendered with JavaScript

Google runs JavaScript in a separate rendering stage. That is why we set the passing standard for item 4 to whether the body content exists in the raw HTML. Understanding the basics of JavaScript search engine optimization (updated March 6, 2026) explains that "If Google's resources are allowed, headless Chromium renders the page and runs JavaScript."

There is no way for the owner to view the rendering result. The same document states that "There's no way to check right away if a page is waiting to be crawled and rendered." If the screen is blank with JavaScript disabled and the curl response also has no body sentence, then that body content appears only after rendering.

3. The canonical URL when content appears at multiple addresses

Google picks one of the duplicate addresses as the canonical URL and consolidates performance and link signals there. Items 5 and 6 help align that choice with your intended canonical URL. How to specify a canonical URL (updated July 15, 2026) describes rel=canonical as "a strong signal that the specified URL should become the canonical URL," and places sitemap inclusion as a weaker signal than that.

The recommendation you can put straight into a development request is internal links. The same document advises that "consistently linking to the URL you consider canonical helps Google identify your preferred page." If links point to addresses with tracking parameters attached, item 6 fails.

4. Pass criteria for Core Web Vitals

While Google states that its ranking systems use Core Web Vitals, it also specifies that there is no single signal for page experience. We set the standard for item 7 to the recommended values rather than a perfect score. Understanding page experience in Google Search results (updated December 18, 2025) states that "Google Search ranking systems use Core Web Vitals," while noting that other page-experience factors do not directly boost search result rankings.

The threshold values are in the Web Vitals (updated October 31, 2024) document. It sets LCP within 2.5 seconds, INP at 200 milliseconds or below, and CLS at 0.1 or below as the criteria for a good experience, and defines the measurement as "the 75th percentile of page loads, segmented across mobile and desktop devices."

5. When site size makes crawl budget relevant

It does not apply to most brand sites, so we did not include it in the checklist. Managing crawl budget (updated August 5, 2026) limits its intended audience to sites with "at least 1 million unique pages" and sites with "at least 10,000 unique pages with content that changes very frequently (daily)," and advises that "if pages seem to be crawled on the same day they're published, you don't need to consult this guide."

If an audit recommends work on crawl budget for a site with fewer than 10,000 pages, ask why. The order for checking proposal items is in What to check when choosing an AEO marketing or GEO marketing firm and the sources AI cites.

6. Additional checks for AI search bots

Because robots.txt applies groups separately for each bot name, checking only Googlebot in item 1 leaves the AI search bot rules outside the scope of your audit. RFC 9309 states, for a bot that has no group under its own name, "crawlers MUST obey the group with a user-agent line with the "*" value, if present". If a Disallow: / left in during development remains in the * group, AI search bots receive the same rule.

Each bot name also serves a different purpose. Anthropic's crawler guidance (April 7, 2026) states that Claude-SearchBot "navigates the web to improve search result quality for users", and separates ClaudeBot as collection for training. You can block only the training bot while allowing the search bot.

Because no public document states that other search bots go through the same rendering, we based item 4 on the raw HTML. If you are considering an agency, we cover the contract items in five points in GEO agency recommendations: why AI answers change every time and how to choose.

If the problems in items 1 through 3 still block indexing, even a newly published post will not be indexed. You can see the order in which PION handles site audits and publishing in the GEO agency service overview, and to mark bot access and indexing status first, the eight items of the 5-minute GEO readiness diagnostic follow the same order.

Frequently asked questions

Where should you start when auditing technical SEO?

In the order of bot access, status code, and index-blocking tags. Because Google's search technical requirements place these three as the minimum conditions for being eligible for indexing, canonical URLs or Core Web Vitals only gain meaning after the first three items pass. PION also builds its checklist in the same order when diagnosing brand sites.

How do you hand a technical SEO checklist to your development team?

Send only the failing items, with four columns: item, verification method, pass criteria, and source document. The pass criteria define completion, and the source column links to the official documentation. The developer can check the requirements without asking you to clarify them. If you hand over the entire table, even items that already pass become work targets.

Are sites built with JavaScript at a disadvantage in technical SEO?

Google states in its documentation that it runs JavaScript with headless Chromium during the rendering stage. However, the same document notes that site owners have no way to directly view a page waiting to be rendered, and there is no public document stating that other search bots perform the same processing. It is safer to check whether the body content exists in the raw HTML using a browser with JavaScript disabled and curl.

What values should you target for Core Web Vitals?

The recommended threshold values are, at the 75th percentile, LCP 2.5 seconds, INP 200 milliseconds, and CLS 0.1 or below. Google states that there is no single ranking signal for page experience, and writes that page-experience factors other than Core Web Vitals do not directly boost search result rankings. Rather than aiming for a perfect score, you can set the recommended values of the three metrics as your passing standard.

Should crawl budget be a checklist item too?

If your site has fewer than 10,000 unique pages, you don't need to include it. Google's crawl budget document limits its intended audience to large sites with at least 1 million unique pages and sites with at least 10,000 pages that change daily. If you are not at that scale, the same document advises that keeping your sitemap up to date and regularly reviewing the page indexing report is sufficient.