Free HTML email pre-flight QA
Paste your HTML email or drop a .html / .zip, and run 41 pre-send checks in seconds — Gmail clipping, Outlook rendering, WCAG contrast, broken links, missing alt text and spam triggers — next to a live preview with simulated Gmail and images-off views (Outlook and dark mode on Pro). Catch the problems before your subscribers do.
The things that break in the inbox.
Deliverability
Gmail's 102 KB clipping threshold, the unsubscribe link, the hidden preheader and spam-trigger words. (Preheader and spam scoring are Pro.)
Rendering
Email width, responsiveness, web fonts, and CSS that the Outlook/Word engine or dark mode won't honour. (Outlook, un-inlined CSS and dark mode are Pro.)
Images & links
Missing alt text, non-https or relative image URLs, image dimensions, and empty or "#" links that go nowhere.
Structure
The email doctype, charset and viewport meta — the boilerplate clients quietly need to render your markup correctly.
Paste, scan, read the fixes.
Paste or upload
Drop your HTML email as raw markup, a .html file or a .zip. Nothing uploads to a server — it's parsed locally in your browser.
Read the report
41 checks grouped into Deliverability, Rendering, Images, Links, Structure, Accessibility and Content, each with a plain-English "how to fix". The report is free; ten advanced findings are Pro.
Preview & send clean
Eyeball the desktop/mobile preview and the simulated client views — each lists exactly what that client strips — fix what's flagged, re-scan, and send with fewer surprises.
Most of the report is free.
No signup to scan, nothing uploaded, and a live preview with simulated Gmail and images-off views — all free. Pro unlocks ten advanced findings — Outlook/Word-engine rendering, spam-trigger scoring, un-inlined CSS, dark mode, the hidden preheader, table semantics, ambiguous link text, CTA consistency, WCAG colour contrast and alt-text quality — plus the simulated Outlook and dark-mode previews, one-click safe auto-fixes with a before/after diff and version compare between amends. A free account hosts the email as a design share link (5 a month, 1 a day, live 3 days) and downloads the design + tech report. Everything else — Gmail clipping, width, unsubscribe, images, links and structure — you see for free.
Private by design
The pre-flight runs entirely in-browser. Your email HTML never leaves your machine — safe for unsent and NDA work.
Previews: devices & clients
Desktop and mobile widths, plus simulated Gmail and images-off views (Outlook and dark mode on Pro) that list what each client strips. Rule-based and labelled — not real screenshots.
A pre-flight, not a render farm
This is a fast static first pass — not full inbox-rendering testing like Litmus or Email on Acid. It catches the predictable problems before you send.
Email QA vs Litmus, Email on Acid and Mailtrap
Paste your HTML or drop a .html/.zip and see Gmail’s 102 KB clip, un‑inlined CSS, Outlook’s Word‑engine risks, missing alt text, placeholder copy, ambiguous links and a missing unsubscribe flagged straight away — and click any finding to highlight it in the email — nothing uploaded, no account. The client tabs add simulated Gmail, Outlook, dark-mode and images-off previews that list exactly what each client strips — rule-based and labelled as such. Litmus and Email on Acid render in REAL inboxes, which we still do not do at all; that starts at $99/month.
| Email QA | Litmus Enterprise | Email on Acid Basic | Mailtrap Email Sandbox | |
|---|---|---|---|---|
| Price | $1 per tool · $35/mo for all 40+ tools · Or $280/yr. No credits, no per‑use fees. | — · no figures published — sales quote only | $99/mo · 1,000 previews, $0.15 overage | $0 free · $17/mo Basic · $14 billed annually |
| Runs with no account, no card and no trial clock | Yes · 31 of the 41 checks plus the desktop and mobile preview run free. The other 10 results — Outlook/Word CSS, spam words, un-inlined CSS, dark mode, preheader, table semantics, ambiguous links, CTA consistency, colour contrast, alt-text quality — appear as locked rows with a log-in prompt. | No · no free tier published; account required | No · trial only, signup required | No · has a free plan (50 emails/mo) but you must create an account and route mail into a sandbox inbox |
| Your email HTML is never uploaded | Yes · Parsed with DOMParser and previewed in a sandboxed iframe on your own machine. Two nuances: remote images/fonts referenced by your HTML are fetched by your browser exactly as a mail client would; and the optional Pro live link check sends the LINK URLS to our server, and a hosted design share uploads the email itself to serve the link — each only when you click it. | No · cloud service receives the HTML | No · cloud service receives the HTML | No · mail is routed into their sandbox |
| No metered previews, credits or overage billing | Yes · Re-run the same email as many times as you like; nothing counts your runs. | — · advertises unlimited previews, but publishes no commercial terms — sales quote only | No · $0.15 per preview over 1,000 on the $99/mo Basic tier | No · metered by email volume; the free plan is capped at 50 emails/mo |
| Drop a .zip and the preview actually renders your local images | Yes · It picks the main HTML, inlines every image as a data URI for the preview, and still runs the checks on your original HTML so relative paths are still flagged. | — · not verifiable from their public pages | — · not verifiable from their public pages | — · not verifiable from their public pages |
| Findings open a plain-English How to fix, not just a red X | Yes · 40 of the 41 checks carry a fix panel — the one gap is the media-query check, which is informational only. Five mechanical findings — layout-table roles, doctype, charset, viewport and the lang attribute — also carry a one-click safe auto-fix with a before/after diff shown first (Pro; the written guidance stays free). Every finding that can point at its element carries a View-in-email button that highlights it in the preview. On the free plan, 10 of the fix panels stay locked with their results. | — · their reports include guidance; a per-finding fix panel is not verifiable from their public pages | — · their reports include guidance; a per-finding fix panel is not verifiable from their public pages | — · not verifiable from their public pages |
| One flat $35/mo covers this plus 39 other production tools | Yes · PRO is $35/mo or $280/yr per user, under $1 per tool — this one is not sold on its own, and the 12 free checks need no plan at all. | No · bundles its own email products (Builder, Proof, Spam Testing) — no ad or image production tools | No · email QA suite only | No · email delivery platform — sandbox plus sending API; no production tools |
| Renders in a real email-client farm | No · Our previews are your own browser engine plus rule-based client simulations, clearly labelled — still not Outlook itself. | Yes · unlimited previews | Yes · 100+ clients and devices | — · no client farm advertised |
| Per-client CSS support matrix | No · Partial: each simulated preview lists exactly which properties that client drops from your code — but that is four profiles (Gmail, Outlook, dark, images-off), not a hundred-client matrix, and accessibility here is alt-text only. | — · not verifiable from their public pages | Yes · HTML code analysis, on Premium $199/mo | Yes · HTML/CSS check advertised; tier not stated on their pricing page |
Prices checked 19 July 2026 on each vendor’s own pricing page. Litmus carries no dollar figure at all — only “Get Enterprise Pricing” and “Contact Sales” — so we quote no number rather than repeat a third‑party estimate. Email on Acid is mid‑migration to Mailgun Inspect (transition began June 2026), so its plans and prices may change; its page states $99/mo without specifying a monthly‑vs‑annual basis, and previews over quota bill at $0.15 each. Its $99 Basic tier buys previews and nothing else: the accessibility tests, HTML code analysis and spam content checks all sit on Premium at $199/mo, so we have marked those rows to the tier that actually has them. Mailtrap’s Basic is $17/mo billed monthly or $14/mo annually, and includes 3 users rather than being per‑user — but it requires routing mail into a sandbox over SMTP or API, so it is a developer workflow, not paste‑and‑go, and its pricing table does not say which tier includes the spam score or HTML checker. A grey “—” means we could not verify that capability on the vendor’s own page, not that it is absent. Our own gaps, stated plainly: no spam‑filter score, no SPF/DKIM or blocklist testing, no send history, no ESP integration and no team review workflow — and the client previews are rule-based simulations, not real-client screenshots. Live link validation exists on Pro: an explicit click sends the link URLs (never the email) to our server, which checks status and redirect chains. Internally only HTML5 Ad QA and Backup‑JPGs are in heavy production use; this one is newer. Not given rows of their own on this table, but true and worth knowing: spam-filter score, auth records and blocklist testing. None of them is affiliated with DigiLakshya.
We hand-code responsive HTML emails that hold up.
Skip the scan-fix-rescan loop. Send us the design and get bulletproof, inline-styled email that renders across Gmail, Outlook and Apple Mail — white-label.
Quick answers.
Is the email QA tool really free?
Do my emails get uploaded to a server?
What does it actually check?
Is this the same as Litmus or Email on Acid?
What's the difference between the desktop and mobile preview?
Can you just build the email for me?
Do these tools use credits or tokens?
QA your email before you send — free.
No signup to scan, nothing uploaded — run 41 pre-flight checks with device previews and simulated client views. Ten advanced findings and the Outlook/dark-mode previews unlock with Pro; everything else is free. Catch the inbox problems early, or hand the build to us.