Sitebulb vs Screaming Frog: which technical SEO tool suits UK agencies?

What to take away

Screaming Frog SEO Spider suits consultants who want raw crawl data and a dedicated log file analyser.
Sitebulb suits agencies that deliver written reports, because it groups findings into prioritised hints.
Both render JavaScript in headless Chrome and run from a desktop machine.
UK GDPR applies to any server log or analytics export you feed into either tool.
Licences are billed in pounds plus VAT, so compare seats and URL limits first.

How the two crawlers compare

The two tools solve the same job with different defaults. Screaming Frog hands you a spreadsheet. Sitebulb groups findings into hints.

Screaming Frog vs Sitebulb

Screaming Frog

Licence model: Annual per user
Platforms: Windows, macOS, Linux
JS rendering: Headless Chrome
Report style: Tabbed tables, CSV
Typical buyer: In-house technical teams

Sitebulb

Licence model: Subscription per user
Platforms: Windows and macOS
JS rendering: Headless Chrome
Report style: Hints, charts, PDFs
Typical buyer: Agencies with reporting duties

Neither tool needs a server install. The crawl runs on your machine, keeping client data local unless you choose a hosted option.

Pricing in pounds and what drives the bill

Both vendors charge in pounds sterling and add VAT at 20%. Screaming Frog sells an annual licence per user. Sitebulb sells a per user subscription, monthly or annually.

Seat count is the main cost lever for Screaming Frog. Check the vendor page before budgeting.

Indicative list prices at the time of writing:

Pricing in pounds

Per seat

Screaming Frog: from £199 plus VAT per year
Sitebulb: from £20 plus VAT per month, entry URL band

VAT-inclusive annual, one person

Screaming Frog: £239
Sitebulb: £288

VAT-inclusive annual, five people

Screaming Frog: £1,194
Sitebulb: £1,440

Screaming Frog's free version caps a crawl at 500 URLs; the paid licence removes that cap. Sitebulb ties plans to a URL allowance per crawl. Entry tiers are typically around 10,000 URLs, with higher bands at 100,000 URLs or more.

Set licence cost against what you charge. See technical SEO audit costs for UK small businesses for where tool time sits in a fixed fee.

UK GDPR and crawl data

Server logs you import for a log file crawl usually hold IP addresses, which are personal data under the UK GDPR. You need a lawful basis, a retention limit and a processing record.

Set a retention period for raw log files. The ICO sets no fixed number of days. A typical window is 30 to 90 days, then delete or anonymise the export. Keep aggregate reports longer only if they no longer identify people.

The ICO's guide to the UK GDPR sets out the accountability records for processors. Strip IP addresses where the analysis does not need them.

Page markup is public, so crawl data is low risk. Log exports are not. Our guide to log file analysis for UK sites covers retention.

British English spellings in crawl reports

Neither crawler ships a British English dictionary. Mixed spellings surface because the source copy is mixed. A US spelling in a title appears in the export as written.

A repeatable check takes three passes.

British English spellings

Export titles, meta descriptions and H1s from the crawl.
Filter for US patterns-or/-our, -ize/-ise, -og/-ogue, -er/-re.
Fix the source, recrawl and confirm the British spelling in the export.

Three-pass British spelling check

Export titles and meta descriptions, sort alphabetically
Run custom search list for American variants
Re-crawl after fixes and compare page counts

Canonical handling and duplicate URLs

Canonical reporting is where the two products differ most. Screaming Frog lists canonicalised URLs as a filter and shows the target. Sitebulb ranks the same issue as a hint.

For example, when a canonical points to a redirect, Sitebulb raises a 'Canonical points to a redirect' hint. In Screaming Frog, filter the Canonicals tab for 'Canonicalised' and check the Canonical URL column against the Redirected URLs report.

Check the rule behind the flag. Google's guidance on consolidating duplicate URLs sets out when rel=canonical is treated as a hint.

Which tool fits which agency

The split is usually about workflow, not crawl quality.

Choose Screaming Frog if an analyst owns the crawl and needs log file work in the same licence.
Choose Sitebulb if the deliverable is a written report.
Run both on large audits, then split the licence cost across projects.

Most agencies end up with one primary licence and a second seat for overflow.

Common questions

Does Sitebulb render JavaScript the same way as Screaming Frog?

Both render in headless Chrome, so JavaScript-heavy templates behave similarly. The difference is how each tool reports rendered against raw HTML.

Can I run either crawler on Windows and macOS?

Screaming Frog runs on Windows, macOS and Linux. Sitebulb runs as a desktop app on Windows and macOS.

Which is cheaper for a small UK agency?

There is no fixed answer, because both vendors sell per user and list prices change. Compare annual cost per seat, add VAT at 20%, then check the crawl limit on your largest site.

Do I need one licence per analyst?

Both vendors sell per user licences. Buy one seat for each person who runs crawls.