Screaming Frog SEO Spider is one of the most respected tools in technical SEO. It crawls websites, finds broken links, audits meta tags, and generates the kind of reports that make site migrations less terrifying. Among its many features, Screaming Frog can also detect tracking tags — scanning your HTML to confirm that a Google Analytics or Meta Pixel snippet is present on each page.
That tag-detection capability is useful. But there is a meaningful difference between knowing a tag exists in the HTML and knowing that tag actually fires, sends the right conversion value, and behaves correctly under different consent states. That difference is the dividing line between Screaming Frog and ConversionOK.
This comparison lays out where each tool excels — honestly — so you can decide which one fits your workflow, or whether you need both.
At a glance
| Dimension | Screaming Frog | ConversionOK |
|---|---|---|
| Approach | Crawls HTML source to detect tag presence | Loads pages in a real browser and tests whether tags fire |
| Platforms covered | Any tag that appears in HTML source | GA4, Google Ads, Meta Pixel, TikTok Pixel, more |
| Setup | Desktop install, configure crawl settings | Enter a URL — no install or tag manager access needed |
| Consent-state testing | Not supported | Tests with and without consent to verify consent mode behavior |
| Value / currency check | Not supported | Verifies conversion values, currencies, and event parameters |
| Duplicate detection | Can flag duplicate tag IDs in source | Detects duplicate conversion fires at the network-request level |
| Pricing | Free (limited) / GBP 259/year (full) | Free tier available / paid plans for monitoring |
| Best for | Site-wide SEO audits and tag inventory | Verifying that conversion tracking actually works end-to-end |
Where Screaming Frog shines
Screaming Frog is not a conversion-testing tool, and it would be misleading to evaluate it purely on that dimension. It is a full-featured SEO crawler, and within that scope it is excellent.
Comprehensive SEO auditing
Broken links, redirect chains, missing meta descriptions, duplicate titles, thin content, hreflang issues — Screaming Frog catches all of these in a single crawl. If you are running a site migration or cleaning up technical debt, it is one of the first tools you should reach for.
Tag inventory at scale
Screaming Frog can crawl thousands of pages and show you exactly which ones contain (or are missing) a specific tracking snippet. If your concern is "did our GA4 tag get deployed to every page after the redesign?", this is a fast answer. It parses the raw HTML for known tag patterns and reports presence or absence.
Industry trust and ecosystem
Screaming Frog has been a staple in the SEO community for over a decade. There are countless tutorials, integrations, and workflows built around it. If you work with SEO agencies or consultants, they almost certainly know how to use it already.
Where ConversionOK fills the gap
Screaming Frog's tag detection works at the HTML level. It reads your page source and checks whether a tag snippet is present. ConversionOK works at the browser level — it loads your page, executes JavaScript, and watches what actually happens on the network.
Real browser execution, not HTML scanning
A tag being in the HTML does not mean it fires. Tags can fail to execute because of JavaScript errors, race conditions with consent management platforms, or conditional logic in Google Tag Manager that prevents the trigger from matching. ConversionOK loads your page in a real browser from an external location, so it catches these failures that a source-code scan will miss. For a deeper look at why "installed" and "firing" are different, see our GA4 tag verification guide.
Conversion value and parameter testing
For e-commerce and lead generation, the conversion value matters as much as the conversion itself. A tag that fires but sends the wrong value — or no value at all — can silently break your ROAS reporting and Smart Bidding. ConversionOK checks the actual values, currencies, and transaction IDs attached to each conversion event. If you have ever had conversion values that do not match between platforms, this is the verification layer you need.
Consent-state testing
With GDPR, DORA, and similar regulations, your tags need to behave differently depending on whether a visitor has granted consent. Screaming Frog crawls without simulating consent states. ConversionOK can test your page both with and without consent, verifying that consent mode is correctly configured and that tags respect the visitor's choice. This is critical for EU traffic and increasingly for other regions.
Ad platform coverage
ConversionOK is purpose-built for the tags that drive advertising spend: Google Ads conversion tags, Meta Pixel and Conversions API, TikTok Pixel, and GA4 e-commerce events. It does not just confirm presence — it verifies that the correct event name, conversion label, and parameters are sent. If you are spending money on ads and your Google Ads conversions are not recording, ConversionOK tells you exactly what is going wrong.
Who should choose which
The honest answer: these tools solve different problems, and many teams will benefit from using both.
Choose Screaming Frog when you need a comprehensive technical SEO audit. Broken links, redirect chains, crawl budget issues, meta tag analysis — this is Screaming Frog's domain. Its tag-detection feature is a bonus that helps confirm deployment coverage, but it is not a substitute for functional testing.
Choose ConversionOK when you need to verify that your conversion tracking actually works. "Works" means the tag fires in a real browser, sends the correct event with the right value, behaves properly under consent restrictions, and does not fire duplicate events. If you are running paid campaigns and need to trust your conversion data, this is the tool that answers that question.
Use both when you have a large site where deployment coverage matters (Screaming Frog to confirm every page has the tag) and conversion accuracy matters (ConversionOK to confirm the tag actually does what it should). A tag that is present on every page but sends the wrong value is arguably worse than a tag that is missing from a few pages — at least the missing tag is obvious.
FAQ
Can Screaming Frog test whether a tag fires correctly?
No. Screaming Frog reads the HTML source of your pages and checks for the presence of tag snippets. It does not execute JavaScript, so it cannot confirm that a tag fires, that the correct event parameters are sent, or that consent logic is respected. For functional testing, you need a tool that runs in a real browser environment.
Do I need both tools?
It depends on your workflow. If your primary concern is SEO health and you want a quick check that tags are deployed across your site, Screaming Frog alone may be sufficient. If your concern is that conversions are firing but not being recorded, or that your conversion values are wrong, ConversionOK addresses those problems directly. Teams that manage both SEO and paid media often find value in using both.
Does ConversionOK replace my SEO crawler?
No. ConversionOK is not an SEO tool — it does not check broken links, meta tags, or page speed. It is focused specifically on whether your conversion tracking works correctly from an external browser. Think of it as the complement to your SEO toolkit, not a replacement.
Conclusion
Screaming Frog tells you that a tag is on the page. ConversionOK tells you that the tag works. Both answers matter, but they answer fundamentally different questions. If you have ever found yourself staring at a tag that looks correct in the HTML but produces zero conversions in your dashboard, you already understand why the distinction matters.
If you want to see what ConversionOK catches on your own site, you can run a free test — no install, no tag manager access, and no risk of clicking your own ads.