Litmus Alternatives in 2026: What to Use Now That Litmus Is Enterprise-Only
Litmus no longer takes self-serve signups. There's no plan you can start today with a credit card — every tier goes through a sales conversation now. That's a reasonable call for an enterprise platform, but it leaves a real gap for developers, freelancers, and small teams who just need to test an email.
Below are six real alternatives, each verified against the vendor's own pricing page rather than an older article or a guess — including one major, very recent change most comparison posts haven't caught up to yet.
The one thing to know first: Email on Acid doesn't exist anymore
If you've read an older "Litmus alternatives" article, it probably named Email on Acid as the obvious enterprise-adjacent pick. As of 2026, that product has been discontinued for new signups. Sinch acquired it and rebuilt it as Mailgun Inspect — not a rename, a ground-up rebuild on the Mailgun platform. Existing Email on Acid subscribers are migrating over starting June 2026.
If you're searching for "Email on Acid," you want Mailgun Inspect. We cover it below, and go deeper in Email on Acid Alternative in 2026 — It's Now Mailgun Inspect.
The alternatives
Sinch acquired Email on Acid and rebuilt it from the ground up as Mailgun Inspect. New customers can't sign up for "Email on Acid" anymore — Mailgun Inspect is the product now, and it's the closest like-for-like Litmus replacement: real screenshots across 100+ clients and devices.
Pricing: Usage-based, starting around $99/mo (Basic — ~1,000 previews, 100+ clients, unlimited users, API access) and ~$199/mo (Premium — adds accessibility, HTML analysis, spam checks). A custom Contract tier needs sales.
Best for: Teams that want Litmus-style real screenshot coverage but self-serve signup instead of a sales call.
A lighter, self-serve email preview and spam-testing tool. Signup is open with a free trial — no sales conversation.
Pricing: We couldn't confirm a current monthly price directly from Testi.at's site at publish time — check their pricing page for the live figure before committing.
Best for: Budget-conscious teams who want a straightforward preview tool without Litmus-scale client coverage.
Not a like-for-like Litmus replacement — Mailtrap's Email Testing product is an SMTP sandbox for developers. Point your app's outgoing mail at it in staging and it catches test emails instead of delivering them, so you can inspect the HTML, headers, and a spam score in one place. It doesn't do cross-client visual screenshots the way Litmus, Mailgun Inspect, Testi.at, or MailViewr do.
Pricing: Free: 50 test emails/mo, 1 sandbox. Paid from $17/mo ($14/mo billed annually): 500 test emails, 3 users.
Best for: Developers who need to catch and inspect emails sent from a dev/staging environment — a different job than visual client testing.
A deliverability and spam-score tool with AI-assisted analysis, not a visual client previewer. Closer to a Mail-Tester or Unspam competitor than a Litmus one.
Pricing: Free: 3 one-time tests, plus free standalone SPF/DKIM/DMARC/BIMI/blacklist checkers (no ongoing free plan). Paid from $23/mo (60 tests/mo) up to $79/mo (unlimited tests + domain monitoring).
Best for: Cold-email and deliverability-focused senders who want AI-assisted content and reputation analysis.
The closest thing here to an all-in-one budget Litmus: visual previews, spam tests, inbox placement tests, and email heatmaps in one tool, with a genuinely free ongoing tier.
Pricing: Free: 10 spam tests, 3 inbox placement tests, 10 previews, 3 device previews per month, no card required. Basic $9/mo, Business $19/mo, Agency $29/mo.
Best for: Marketers who want previews, spam scoring, and inbox placement together without an enterprise contract.
Preview and testing tools that are free forever, with 5 free previews before signup — Gmail, Outlook, and Apple Mail across 8 clients, dark mode simulation with published per-client accuracy figures, SpamAssassin spam scoring with a per-rule breakdown, and an accessibility checker. The drag-and-drop builder is free while it's in early access.
Pricing: Preview, code editor, MJML tooling, dark mode, and accessibility: free forever, 5 previews before signup. Builder + full Email Readiness suite: free during early access.
Best for: Developers, freelancers, and small teams who want to build and test in the same place without a subscription.
Side-by-Side
| Tool | Self-serve? | Cheapest paid tier | What it actually does |
|---|---|---|---|
| Litmus | No — sales only | Not published | Real screenshots, very wide client matrix, analytics, team workflow |
| Email on Acid / Mailgun Inspect | Yes (free trial) | ~$99/mo | Real screenshots across 100+ clients |
| Testi.at | Yes (free trial) | Not confirmed — check site | Lightweight visual preview + spam check |
| Mailtrap | Yes (free tier) | $17/mo | SMTP dev sandbox, not visual client rendering |
| MailGenius | Yes (limited free) | $23/mo | Spam / deliverability scoring, AI analysis |
| Unspam.email | Yes (free tier) | $9/mo | Previews + spam tests + inbox placement |
| MailViewr | Yes — 5 free, then sign in | Free (builder in early access) | Preview + dark mode + spam + accessibility + builder |
Which one should you actually use?
- You need real screenshots across a long tail of obscure clients: Mailgun Inspect (formerly Email on Acid) is the closest Litmus replacement that still takes self-serve signups.
- You want previews, spam score, and inbox placement in one budget tool: Unspam.email has the most complete genuinely-free tier of the group.
- You're focused on deliverability and cold-email reputation: MailGenius is purpose-built for that, not for visual rendering.
- You need to catch and inspect emails sent from a dev environment: Mailtrap solves a different problem than the rest of this list and solves it well.
- You want to build and test an email in one place, free, with 5 previews before you need an account: that's what we built MailViewr for.
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