Email on Acid

Email on Acid (now part of AWeber) provides client-rendering previews, accessibility checks, link validation, image and load-time analysis, spam testing, and a campaign precheck workflow. Direct competitor to Litmus with broadly similar coverage and typically lower entry pricing.

The question here is which one a backend engineer would rather operate. That means SDK depth in the language already in use, whether a retry can safely be replayed, how much the event log tells you when a customer says the email never arrived, and whether the pricing curve stays sane as volume grows.

Against password resets, receipts, and magic links shipped from application code, Email on Acid covers developer experience, and does not cover SDK breadth, idempotency keys, event stream, and webhook coverage. Whether that gap matters depends on how central those are to the build.

• DX score: 7/10
• SDKs: None
• Idempotency keys: No
• Operating since: Not published
• Event stream: No
• Best published rate per 1,000: Tiers not published in comparable form
• Webhooks: No
• Deliverability: Not applicable; preview and QA, not a sender.
• Free tier: 7-day free trial; no permanent free tier

Not applicable; preview and QA, not a sender.

Teams that want Litmus-grade previews at a lower entry price.

Teams already standardized on a sending platform with built-in previews.