For transactional email
Consider SMTP2GO for website-generated messages, form notifications, account notices, and other outbound system email.
Explore SMTP2GOAvailableFree browser-local analysis
Render Blocking Resource Analyzer
SiteTend Render Blocking
Find blocking stylesheets, synchronous scripts, delayed font discovery, and resource-ordering problems in a pasted page head.
Your input stays private.HTML is analyzed in your browser.
Paste page head HTML
Add the head section or a complete HTML document.
Review the critical path
Start with synchronous scripts and blocking stylesheet chains.
Your analysis will appear here
Paste HTML and select Analyze resources.
How to improve
Shorten the critical rendering path carefully
Prioritize above-the-fold styles, let independent work load without blocking parsing, and add early hints only for resources that are truly critical. Measure before and after each change.
Questions
Render Blocking Analyzer FAQ
What does the Render Blocking Resource Analyzer check?
It reviews stylesheet links, head scripts, font loading, duplicates, resource order, broad CSS bundle signals, and early connection opportunities.
Does every stylesheet block rendering?
Applicable stylesheets normally block first render. Alternate media and intentional loading patterns can make a stylesheet non-blocking.
Should every script use async?
No. Use defer when execution order matters, async for independent scripts, and test behavior after changing loading attributes.
Can pasted HTML reveal actual resource size?
No. This version can measure inline CSS and identify filename hints, but external transfer size requires network measurement.
Apply the result
From finding to verified fix
Interpret the finding
A flagged resource is a review candidate. Its actual impact depends on when it is needed and how much work it adds to the critical path.
Common causes to inspect
- Synchronous scripts in the head
- Large global stylesheets
- Font stylesheets and imports discovered late
Practical next steps
- Confirm whether the resource is required above the fold
- Defer or split only noncritical work
- Measure rendering again after each change
What this check cannot prove
Static markup cannot reproduce network timing, dependency waterfalls, cache state, or runtime script behavior.
Recommended resources
Useful next steps for operating a website
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