Free Litmus Alternative — HTML email pre-flight QA

Yes. Paste your HTML or drop a .html/.zip and the report runs in your browser at no cost, with no signup — Gmail clipping, width, unsubscribe, images, links and structure checks plus the live preview and simulated Gmail and images-off views are all free. Ten advanced findings — Outlook/Word-engine rendering, spam-trigger word scoring, un-inlined CSS, dark-mode hints, the hidden preheader check, layout-table semantics, ambiguous link text, CTA consistency, WCAG colour contrast and alt-text quality — plus the simulated Outlook and dark-mode previews unlock with Pro, which is $35/mo or $280/yr across the whole Studio-Tools suite. See tools pricing.

No. The whole pre-flight is parsed locally in your browser — your HTML never leaves your machine, which makes it safe for unsent campaigns and client work under NDA. Litmus and Email on Acid work differently by design: you send your email to their cloud so they can render it in real clients. Neither approach is wrong; ours just never sees your email. More on how we handle files.

No — and we won't pretend it is. Litmus and Email on Acid render your email inside real inbox clients (Litmus advertises 100+ clients and devices) and return true screenshots. Ours reads your HTML, catches the common, predictable code problems, and adds simulated Gmail, Outlook (Word-engine), dark-mode and images-off previews — rule-based approximations from each client's documented CSS support, each listing exactly what that client strips from your code. Clearly labelled as simulations, never sold as screenshots. If you need client-by-client rendering proof, Litmus is still the right tool. Most rendering bugs, though, start as code issues — and those are exactly what this checker catches, free.

41 checks, grouped into Deliverability, Rendering, Images, Links, Structure, Accessibility and Content: Gmail's 102 KB clipping threshold, email width, the unsubscribe link, the hidden preheader, spam-trigger words, un-inlined <style> CSS, CSS the Outlook/Word engine won't honour, web fonts, responsiveness, dark-mode hints, image alt text, absolute-https image URLs, image dimensions, empty or "#" links, security-gateway rewrapped links (Proofpoint urldefense, Microsoft SafeLinks, Mimecast — pasted from a scanned inbox, they break for everyone outside that org), and the doctype/charset/viewport — each finding with a plain-English "how to fix", next to a desktop/mobile preview with simulated Gmail, Outlook, dark-mode and images-off client views.

Three honest cases: when a high-stakes send needs final screenshot proof across real clients and devices; when you need seed-list spam testing against actual inbox providers rather than code-level spam signals; and when your team lives on their analytics and ESP integrations. A workflow many teams use: run every build through our free pre-flight first, then spend the paid renders only on the sends that warrant them.

No — never. Use and preview every tool with no account. A free account downloads any single result at full size, with no daily limit. PRO adds Download all, every banner size, more share links and saving to your account. A few things keep a small free allowance: QA checks (2 a day with no account, 5 with a free one) and hosted share links (5 a month, 1 a day, live 3 days). PRO is a flat $35/month ($280/year) for unlimited use of all 35+ tools: no credit packs, no top-ups, no per-use fees. Many comparable tools bill per credit (remove.bg, CloudConvert, AdCreative.ai) — here one flat subscription covers everything. See tools pricing.