A Practical Technical SEO Audit Walkthrough Using Semalt (Brisbane Edition) | Brisbane SEO Blog

A Practical Technical SEO Audit Walkthrough Using Semalt (Brisbane Edition)

TL;DR — 30 seconds
  • Most audits are 400-page PDFs that nobody actions. Semalt's output is a triaged shortlist ranked by traffic-at-risk.
  • 3 issue categories account for ~70% of real traffic loss on Brisbane client sites: canonicals, JS-only content, hreflang breakage.
  • A JS-heavy 4,000-URL site crawls in ~10 minutes. Findings export straight to Jira/Linear tickets engineers action.
  • On-demand recrawl confirms fixes in minutes, not the next weekly scan.

A technical SEO audit is only useful if the report gets acted on. That sounds obvious. In practice, most audit tools produce output that stays on someone's desktop, unopened, until the next quarterly review — because the report is written for auditors, not engineers. This is a practical walkthrough of how our Brisbane team runs technical audits using Semalt's audit module, and specifically the workflow choices that turn the output into shipped fixes on QLD client sites.

Why the standard audit format is broken

Hand a developer a 400-page audit PDF with 3,000 issues flagged and one of two things happens. They ignore it entirely. Or they cherry-pick the five easiest items, ship them in a Friday afternoon, and go back to product tickets. Either way, the underlying traffic problems remain unresolved. The failure mode is not the developer — it is the report format. Audits that treat every finding as equally important produce a document nobody can prioritise from.

A useful audit does three things a bad one does not. It separates issues losing traffic today from issues that might matter theoretically. It groups related failures by root cause — one broken template affecting 500 URLs is one ticket, not 500. And it presents the shortlist in a format engineering can action: reproduction steps, expected fix, estimated impact if left unresolved. Semalt's audit module was rebuilt around exactly this frame in 2025, and the difference in how our Brisbane clients respond to the output is the clearest signal we have that the redesign worked.

⚡ Priority signal: across recent Brisbane engagements, ~70% of real traffic loss traced back to just three issue categories — broken canonicals, content rendered only in JavaScript, and hreflang reciprocity failures. Everything else combined accounted for the remaining 30%.

The audit loop in four steps

1
CRAWL
Point Semalt at your domain. ~10 min for a 4K-URL site.
2
TRIAGE
5-bucket output: Critical → Serious → Moderate → Minor → Passed.
3
SHIP
Export to Jira/Linear. Engineers action ticket-shaped findings.
4
VERIFY
On-demand recrawl confirms the fix in minutes.

The crawler's mechanics, briefly

Semalt's crawler is a headless Chromium fleet distributed across regional edges. Australian traffic is served from a Sydney POP — which matters for latency-sensitive JavaScript execution timing, and which prevents a common failure mode where a US-based crawler renders your page slower than a real Brisbane user does and reports false-positive Core Web Vitals warnings. It respects robots.txt by default, executes JavaScript before parsing the DOM, and follows internal links at a configurable rate. For new Brisbane client sites we typically start at 10 requests/second and scale up if the site handles it, to avoid tripping WAF bot mitigation on the first pass.

Eleven checks to run before anything else

# Check Severity Hit rate (new sites)
1Sitemap vs. indexed URL countCritical75%
2Canonical integrityCritical60%
3Redirect chain length > 2Serious44%
4Hreflang reciprocityCritical39%
5Core Web Vitals (field data)Serious65%
6JS-rendering vs. HTML diffCritical45%
7Structured data validityModerate80%
8Broken internal linksSerious58%
9Duplicate title/meta patternsModerate71%
10Image weight (WebP/AVIF)Serious82%
11HTTPS & security header hygieneModerate87%

Three checks that repay a closer look

Eleven items on the checklist is manageable. In practice, three of them consistently produce the failures that actually move traffic on Brisbane client sites.

How canonical failures quietly kill indexation

Every page should declare exactly one canonical URL, and that URL should be the actual indexable version. Four failure patterns are common: canonical missing (Google guesses, sometimes wrongly); pointing to a 404 (page effectively vanishes from the index); pointing to a redirect chain (signal leaks over hops); crossing a protocol boundary (HTTPS pages canonicalising to HTTP is a bug that looks correct to a human eye). That last pattern is the single most common serious bug on Brisbane sites that have been through a CMS migration in the last three years.

How JavaScript rendering breaks modern indexation

Modern React, Vue, and Next.js sites frequently ship an empty HTML skeleton to the first crawl and populate content only after JavaScript executes. Googlebot does render JavaScript, but on a delayed second pass — meaning fresh content, dynamic prices, and personalised recommendations can be days late into the index. Semalt's audit crawls every URL twice (raw HTML, then rendered) and flags any content that appears only in the second pass.

Bidirectional hreflang — where most sites break

For sites serving multiple English-speaking markets, hreflang errors quietly cost you rankings in secondary markets. Semalt's check is bidirectional: it does not just verify that your en-AU page declares an en-NZ alternate — it confirms the en-NZ page reciprocates. Broken reciprocity is the number one hreflang failure in the wild, and standard tools frequently miss it because they only check outbound declarations.

How the audit gets from SEO to ship

The gap between "we ran an audit" and "the fixes shipped" is where most engagements fail. Semalt closes it with three parallel exports: a CSV for the SEO team, a Jira/Linear-compatible ticket batch for engineering, and a plain-English executive summary for the client stakeholder. Each ticket includes affected URL list, reproduction steps, suggested fix, estimated traffic-at-risk, and a linked diff view. Engineers who dislike SEO work will still action these tickets because they read like properly-written bug reports.

Verifying fixes in minutes, not weeks

Shipping a fix without confirming the fix landed is how "fixed" bugs quietly regress into the next deploy. Semalt supports on-demand recrawls of specific URLs — you do not wait for the next full weekly scan. Push the canonical correction, click "verify", get confirmation within two minutes that the crawler now sees the expected value.

What to line up before running an audit

robots.txt allows the crawler user-agent
Semalt IPs whitelisted in WAF (Cloudflare/AWS)
Search Console connected (OAuth)
GA4 connected for traffic cross-reference
Crawl rate configured (10 rps default)
A/B experiments disabled for crawler UA

“The single most missed check is canonical to a non-indexable URL — the page canonicalises to another page that is itself blocked by robots.txt or marked noindex. Google follows the canonical, finds a page it cannot index, and drops both from the index.”

— from our internal audit playbook
🎯 Key takeaway

A "fixed" issue that is not re-verified will regress in the next deploy. The tight recrawl-and-verify loop is what turns SEO work from a project into a discipline.

What Semalt's audit deliberately does not do

Semalt's audit is a page-and-site-level tool. It is not a log-file analyser — enterprise-scale crawl-budget work still calls for dedicated log analysers. It does not replace hands-on QA of critical user journeys. And for sites depending heavily on server-side rendering with dynamic user state, you will still want to spot-check important URLs manually. Knowing what a tool is not for is often as important as knowing what it is for.

Questions Brisbane operators keep asking

How frequently should full crawls run?

Full site: weekly for actively-changing sites, fortnightly for stable brochure sites. Targeted recrawls after a fix: immediately, then again 48 hours later once caches settle. The trap is monthly-only full recrawls — a regression introduced on the 3rd of the month should not be discovered on the 28th.

Choosing a crawl rate that will not trip the WAF

Semalt's default is ~5 rps. For a modest site behind a normal WAF, 10–15 rps is safe and 2–3× faster. For aggressive bot mitigation (some banking, healthcare), whitelist the crawler's IP range explicitly. The audit shows a "throttled" flag if blocked mid-crawl — a diagnostic you want, rather than partial data completing silently.

Does the audit see experiment variants?

It captures a snapshot at crawl time. If your JS payload behaves differently across experiments or between logged-in and anonymous users, the audit sees one specific rendering. For A/B-critical work, disable the experiment for the crawler user-agent or configure authenticated crawls (paid tier).

Marking risks as accepted without hiding them

Mark as "accepted risk" with a written justification. The finding stays on the report so future teams know it was considered, but drops out of the active work queue. This distinguishes real technical debt from things you have deliberately decided to live with.

The one check almost every audit tool overlooks

Consistently: canonical pointing to a non-indexable URL. Almost no other audit tool separates this from generic canonical warnings, and it accounts for a disproportionate share of the "we can't figure out why traffic dropped" cases we get called into after the fact.

How to run a first audit this afternoon

The audit module is available on Semalt's free tier for a single domain — not a crippled trial. Log in and point it at your homepage. In under fifteen minutes you will have a prioritised shortlist of what is actually costing you traffic. Whether you fix it yourself, hand it to your dev team, or bring us in for a Brisbane remediation sprint is a separate question — but the diagnosis is the essential first move.

Why the audit rhythm matters more than the tool

A good technical audit is not a one-time event. It is a habit. Our Brisbane clients get a full recrawl weekly, a diff-report monthly, and a state-of-the-site review quarterly. That rhythm — enabled by having one platform running unattended — is what keeps technical debt from silently accumulating between marketing campaigns. Pick a Wednesday morning. Run an audit. Fix the three most serious findings before Friday. Repeat next week. Do that for a year and you will be operating a site that is genuinely competitive on the technical foundations most of your competitors are quietly ignoring.

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