Glossary · Marketing, CRM & Growth
Email on Acid
Overview
What Email on Acid is
Email on Acid is a subscription-based platform focused on pre-deployment email testing, launched in 2009 in Denver, Colorado. It is used by developers, marketers, and enterprise teams to verify how emails render and perform before they reach subscribers.
In 2021 it became part of Sinch (through the acquisition of the Pathwire portfolio, which also includes Mailgun and Mailjet) and operates under the Sinch brand while continuing as a standalone product.
How Email on Acid works
You upload or paste your email HTML, or connect your ESP, and the platform produces screenshots of how the email renders across a range of email clients, devices, and screen sizes. It also runs pre-send checks including spam filter analysis, deliverability signals, link validation, image checks, and accessibility review.
Features such as Campaign Precheck bundle these checks into a guided workflow so teams can catch and fix issues in one place before hitting send, and the platform supports collaboration and approval steps.
Why Email on Acid matters
Because email clients render HTML inconsistently and deliverability problems can silently sink a campaign, testing before send protects both brand perception and revenue. Accessibility and spam checks also help emails reach and be usable by more recipients.
Email on Acid competes most directly with Litmus; the two offer overlapping capabilities, and choice often comes down to workflow, integrations, and pricing. Both are paid tools, and coding frameworks like MJML can reduce rendering issues before testing begins.
Where we use it
Related Zen in Tech services
How our team puts Email on Acid to work in real projects.
FAQ
Email on Acid — common questions
What is Email on Acid used for?
Email on Acid is used to test emails before sending, generating rendering previews across many email clients and devices and running spam, deliverability, link, and accessibility checks to catch problems early.
Who owns Email on Acid?
Email on Acid is part of Sinch, which acquired it through the Pathwire portfolio in 2021. It continues to operate as a standalone product under the Sinch brand.
How is Email on Acid different from Litmus?
Both are paid pre-send email testing platforms with rendering previews and inbox checks. They overlap heavily, so the choice usually depends on workflow, integrations, collaboration features, and pricing.
Need Email on Acid done right?
Book a free consultation and we’ll map the fastest, most cost-effective path for your project.
Knowledge hub
From our knowledge hub
All articles →What Is Digital Marketing? Channels, Strategy & ROI Explained
What is digital marketing? A complete guide to the channels (SEO, PPC, social, email, content), how they work together, and how to measure ROI.
Read · 9 min →Digital MarketingEmail Marketing vs Social Media: Where to Invest
Email marketing vs social media: which delivers better ROI, how they differ, and how to use them together for compounding growth.
Read · 7 min →SEOLocal SEO for Oilfield Services: Getting Found in Texas Energy Markets
Local SEO for oilfield services: optimize your Google Business Profile, build service and basin pages, and earn reviews to get found in Texas energy markets.
Read · 4 min →