Audit in your sidepanel.
Inspect elements live.
Analyze your HTML email layouts for CSS compatibility, spam triggers, and accessibility side-by-side inside your browser. Point, click, fix.
Supports local files & live dashboards
How it works
Three clicks to pre-flight confidence
Open your email render
Launch any local HTML file render in your browser, or view templates in Mailgun, Klaviyo, Hubspot, or your own developer dashboard.
Activate Element Inspector
Click Inspect Mode. Hover and point-and-click directly on any container block, CTA button, or text node to isolate CSS support errors.
Audit in the sidepanel
Watch real-time diagnostics calculate side-by-side. Expand warnings to see visual lightbulb code fixes and ship flawlessly.
What you get
Everything email developers need
Visual Element Inspector
Hover over any block, table, button, or image directly inside your email render to pinpoint exactly which styles break.
Side-by-Side Audits
Keep your email on the left and live preflight scores in your browser sidepanel on the right. Zero context switching.
CSS Support Warning
Actionable alerts for flexbox, grid, gap, aspect-ratio, and styles that Gmail, Outlook, or Yahoo silently strip.
Accessibility Diagnostics
Ensure optimal contrast ratios and confirm all images contain robust alt tags for screen readers.
Deliverability Checks
Instant payload file size verification and automated Gmail 102KB clipping warning safety checks.
Auto-Reload Sync
The sidepanel automatically refreshes your compatibility audit whenever you hit save in your local code editor.
Coverage
15 clients, 95%+ of real email opens
Every preview runs through real rendering engines — not approximations, not screenshots of screenshots.
Free to start
- 15 free local audits per day — no account needed
- Sign up free for 30 audits per day
- No local loopback requirements
- Fully functional visual element inspector
- Contrast ratio & image alt accessibility diagnostics
Need more? See pricing
Install the Extension
Available on Chrome Web Store. Install once, audit in any browser tab.
Add to Google ChromePowered by Emailens — email QA for developers