GTmetrix vs Sitebulb in 2026: Page speed testing vs a full technical SEO crawler
GTmetrix tells you why one page is slow. Sitebulb crawls the whole site and hands you 300+ prioritized hints on everything else that could be wrong with it.
GTmetrix
Sitebulb- Sitebulb includes JavaScript crawling on every plan, including its cheapest Lite tier at $18/month, with no separate rendering add-on required.
- GTmetrix offers a genuinely usable free tier with waterfall charts and Core Web Vitals. Sitebulb has no permanent free plan, only a 14-day trial.
- Sitebulb ships 300+ prioritized SEO hints on its Pro and Cloud plans, each ranked by severity with built-in educational context.
- GTmetrix offers API access from its $18/month Starter plan. Sitebulb does not list API access in its pricing tiers at all.
- Sitebulb Cloud can crawl up to 10 million URLs per audit, a scale GTmetrix, built for single-page testing, does not address.
- Sitebulb has announced an MCP server for AI-assisted audit querying, currently in a waitlist phase, distinct from AI search visibility tracking.
GTmetrix and Sitebulb get mentioned in the same breath because both show up in technical SEO toolstacks, but they are not really rivals. GTmetrix is a page speed testing tool: point it at a URL and get a waterfall chart and Core Web Vitals breakdown back in seconds, free of charge. Sitebulb is a site crawler: it visits every page it can find, renders JavaScript along the way, and returns over 300 prioritized hints ranked by how much they are likely to matter, starting at $18 a month. Where they genuinely overlap is monitoring and reporting, both offer scheduled checks and both can produce data for client-facing reports, but the core jobs they do are different enough that most serious technical SEO setups will eventually run both.
The tools at a glance
GTmetrix
Page speed analysis with Lighthouse, Web Vitals, waterfall charts, and performance monitoring.
GTmetrix runs a single page through a real Chromium browser and returns a waterfall chart, Core Web Vitals scores, and a Lighthouse-based grade, with a free tier that needs no credit card and is useful on its own for a one-off check. Paid plans starting at $5.50 a month add scheduled monitoring, more test locations, mobile device emulation, and, from the $18 Starter tier, API access.
What GTmetrix is not built to do is crawl an entire site looking for broken links, missing metadata, or canonical issues. It has no concept of a site-wide audit, it only ever looks at the pages you point it at, one at a time. That narrowness is deliberate: the waterfall chart and Core Web Vitals detail it delivers on that single page remain some of the clearest diagnostics available in any freely accessible tool.
For agencies running both performance testing and full technical audits, GTmetrix typically sits alongside a crawler rather than replacing one. It answers "is this page fast" well; it has nothing to say about redirect chains, duplicate content, or heading structure across a thousand-page site.
| Feature | Free Free | Solo $5.50/mo | Starter $18/mo | Growth $40/mo |
|---|---|---|---|---|
| On-demand tests | Limited | 50/mo | 200/mo | Unlimited |
| Monitored pages | 0 | 1 | 5 | 20 |
| Test locations | 1 | 7 | 14 | 22+ |
| Mobile testing | No | Yes | Yes | Yes |
| API access | No | No | Yes | Yes |
Sitebulb
Website crawler for technical SEO audits with prioritized hints and visual reporting
Sitebulb crawls a site and turns the results into more than 300 prioritized Hints, each ranked by severity and paired with educational context explaining why it matters, not just what it is. JavaScript crawling is included on every plan, including the $18 Lite tier, which is notable since several competitors charge extra or require an upgrade for rendered crawls.
The product splits into Desktop, which runs locally and caps out at 500,000 URLs per audit on the Pro plan, and Cloud, which adds team collaboration, automated recurring crawls, and capacity up to 10 million URLs starting at $125 a month. Both come with a 14-day free trial and no credit card required, and Sitebulb integrates with Google Analytics, Search Console, Sheets, and, on Cloud, Looker Studio.
Sitebulb does not test page speed, waterfall data, or Core Web Vitals in the way GTmetrix does, and its pricing tables do not list an API for pulling audit data programmatically. What it has instead is a Model Context Protocol server in development, currently waitlisted, aimed at letting practitioners query audit data through AI tools rather than exposing a traditional REST API.
| Feature | Lite $18/month | Pro $42/month | Cloud From $125/month |
|---|---|---|---|
| URLs per audit | 10,000 | 500,000 | Up to 10 million |
| SEO Hints | 100+ | 300+ | 300+ |
| JavaScript crawling | Yes | Yes | Yes |
| GA / GSC / Sheets integration | Yes | Yes | Yes |
| Scheduled audits | No | Yes | Yes |
| Audit comparisons | No | Yes | Yes |
| Customized PDF reports | No | Yes | Yes |
| Team collaboration | No | Add-on +$11/user | Included (2+ users) |
Head-to-head feature comparison
| Feature | GTmetrix | Sitebulb |
|---|---|---|
| Free plan / trial | Yes (free tier, no card required) | No (14-day trial, no card required) |
| Starting paid price | $5.50/mo | $18/mo |
| Page speed / Core Web Vitals testing | Yes | No |
| Site crawler & prioritized technical audit | No | Yes (300+ hints) |
| Waterfall / resource-level diagnostics | Yes | No |
| Scheduled / recurring monitoring | Yes (paid plans) | Yes (Pro+) |
| Branded PDF reporting | No | Yes (Pro+) |
| API access | Yes (Starter+) | No |
| Multi-location speed testing | Yes (paid plans) | No |
| JavaScript-rendered crawling of full site | No (single-page test only) | Yes (all plans) |
Which should you choose?
GTmetrixSitebulbSitebulbGTmetrixSitebulbSitebulbThese tools are complementary more often than they are competing. GTmetrix has nothing to say about redirect chains, duplicate content, or heading structure, and Sitebulb has nothing to say about waterfall timing or Core Web Vitals thresholds on a specific page. Agencies that do both performance work and full technical audits tend to run GTmetrix for the former and a crawler like Sitebulb for the latter, rather than picking one over the other.
Bottom line
Start with GTmetrix if the immediate job is fixing page speed and you either have a crawler already or do not need one yet. Start with Sitebulb if you need a full technical SEO audit with prioritized, explainable findings and JavaScript rendering included at every tier. For a shop running both performance diagnostics and technical audits as standing services, budgeting for both tools is the realistic outcome rather than choosing between them.
Frequently asked questions
Can Sitebulb replace GTmetrix for page speed testing?
Not really. Sitebulb is a site crawler focused on technical SEO issues like broken links, duplicate content, and metadata problems, and it does not test page speed, generate a waterfall chart, or report Core Web Vitals the way GTmetrix does. If diagnosing a slow page is the task, GTmetrix is still the tool built for that, even if Sitebulb is already running full-site audits for you.
Does GTmetrix crawl an entire website like Sitebulb does?
No. GTmetrix tests one URL at a time and has no crawling functionality, so it cannot find broken links, duplicate content, or canonical issues across a site the way Sitebulb's 300+ Hints system does. GTmetrix and Sitebulb are typically used together rather than as substitutes for each other.
Is Sitebulb worth it over GTmetrix if I only care about Core Web Vitals?
No, if Core Web Vitals is genuinely your only concern, GTmetrix is the more direct and cheaper option at $5.50 a month with a usable free tier, since Sitebulb does not test page speed or Web Vitals at all. Sitebulb's value is in full-site technical auditing, which is a different job than Core Web Vitals monitoring.
Which tool has an API, GTmetrix or Sitebulb?
GTmetrix has an API starting on its $18/month Starter plan, letting you trigger tests and pull results programmatically. Sitebulb does not list API access in any of its pricing tiers; instead it has an MCP server in development, still on a waitlist, aimed at letting AI tools query audit data rather than exposing a conventional REST API.
Does Sitebulb include JavaScript rendering, or is that an extra cost like with some crawlers?
JavaScript crawling is included on every Sitebulb plan, including the $18/month Lite tier, at no additional cost. This is worth noting because several competing crawlers charge separately for rendered crawls or gate them behind a higher tier, while Sitebulb builds it into the base price.