What is a good alternative if I don't need 100+ client screenshots?

If you mainly test Gmail, Outlook, and Apple Mail — which cover the large majority of opens — a lighter tool is usually enough. MailViewr's preview and dark mode testing give you 5 free previews before signup, the accessibility checker is free forever with no signup, and the builder is free during early access. See the full comparison in Litmus Alternatives in 2026 for budget options like Unspam.email and Testi.at as well.

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ComparisonAug 13, 20265 min read

Looking for an Email on Acid Alternative in 2026? Start with What Actually Replaced It.

Q: Can I still sign up for Email on Acid?

No. Email on Acid is no longer available as a standalone product for new customers. It was rebuilt from the ground up on the Mailgun platform and relaunched as Mailgun Inspect. Existing Email on Acid subscribers began migrating to Mailgun Inspect from June 2026, at contract renewal for annual plans.

Q: How much does Mailgun Inspect cost?

Mailgun Inspect uses usage-based pricing starting with a Basic plan around $99/month (roughly 1,000 email previews, 100+ clients and devices, unlimited users, API access) and a Premium plan around $199/month that adds accessibility testing, HTML code analysis, and spam content checks. Both have shown self-serve free trial signup; a custom Contract tier requires sales. Confirm current figures on Mailgun's own pricing page before budgeting, since usage-based plans change.

MailViewr Team— If you're searching for an "Email on Acid alternative," the first thing to know is that the platform wasn't just rebranded — it was replaced. Here's what happened, what its successor looks like, and when choosing a lighter alternative makes more sense.

Email on Acid, the email testing platform, no longer exists as a product you can sign up for. Sinch (the parent company of Mailgun) acquired it and rebuilt it — not renamed it — on top of Mailgun's core infrastructure. The result is Mailgun Inspect.

What actually happened to Email on Acid?

Mailgun Inspect covers the same category of pre-send QA and rendering tests Email on Acid always has, but ties directly into Mailgun's sending engine and analytics instead of standing alone.

The migration timeline

June 2026 rollout: existing Email on Acid subscribers began transitioning to Mailgun Inspect. Annual contracts migrate as their terms renew.
No new legacy signups:the standalone "Email on Acid" product is closed to new users. Everything now runs through Mailgun Inspect.
Fresh slate: historical test data and past previews do not carry over to the new platform.

Mailgun Inspect: pricing & features

Pricing shifted from legacy flat seats to usage-based tiers:

Basic — around $99/month: roughly 1,000 previews per month, 100+ clients and devices, unlimited seats, API access, self-serve free trial.
Premium — around $199/month: roughly 2,000 previews per month, plus accessibility validation, HTML code analysis, and spam checks.
Enterprise / Contract — custom: custom preview allotments and dedicated support.

Key takeaway:

Unlike Litmus, Mailgun Inspect still allows self-serve signup without forcing you into an enterprise sales call. Check Mailgun's own pricing page for current figures before budgeting — these are usage-based plans and the numbers move.

Do you actually need a $100–$200/month testing suite?

Coverage across 100+ obscure email clients matters if you're an enterprise sending at massive scale, where a broken layout in Lotus Notes or an old Android client loses revenue.

For most teams, Gmail, Apple Mail, and Outlook account for 90%+ of total opens. Paying $1,200–$2,400 per year just to check standard rendering across three client ecosystems is overkill.

And if you're building the email as well as testing it, a separate design tool plus a separate testing suite is two subscriptions and an export step. A tool that does both — like MailViewr's Email Builder — cuts that down to one.

Where MailViewr fits

If you want fast, focused testing without the enterprise overhead:

Instant core previews: test rendering across the 8 dominant environments (Gmail, Outlook, Apple Mail across desktop, iOS, and Android), including dark mode and accessibility checks — free, no account required.
Spam & deliverability analysis: run SpamAssassin checks with granular, rule-by-rule breakdowns at zero cost.
Email Readiness Suite: visual drag-and-drop builder (Studio) and complete pre-send validation, free during early access — see the full free vs. early-access breakdown.

For the full comparison including Testi.at, Mailtrap, MailGenius, and Unspam.email, see Litmus Alternatives in 2026.

FAQ

Can I still sign up for Email on Acid?

How much does Mailgun Inspect cost?

Is Mailgun Inspect the same product as Email on Acid, just renamed?

What's a lighter alternative if I don't need 100+ client screenshots?

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