Paste Gmail's "Show original" output, a .eml file, quoted-printable body, base64 content, or JSON from an ESP API. EmailQA auto-detects the format and renders the email exactly as your subscribers see it — no manual decoding, no command-line tools.
No credit card required
Pasting raw email source into any other preview tool gives you gibberish. Here's what the same content looks like in EmailQA vs. a standard preview.
Content-Type: text/html; charset=3DUTF-8 Content-Transfer-Encoding: quoted-printable <!DOCTYPE html> <html> <body style=3D"margin: 0; padding: 0;"> <h1 style=3D"color: #ff6= 600;">Welcome=E2=80=87back!</h1> <p>Your order =E2=80=94 = ready to ship.</p> </body> </html>
Rendered literally. Users see =3D, =E2=80=87, broken line wraps — and the preview is unusable.
Your order — ready to ship.
Decoded, rendered, and ready for testing. A toast confirms which format was detected.
EmailQA detects the format automatically. Clean HTML falls through untouched. Everything else gets decoded before render.
The default encoding for most ESP-sent emails. Full of =3D, =E2=80=87 sequences and soft line breaks.
<h1 style=3D"color: #ff6= 600;">Welcome=E2=80=87back</h1>
Common source: Gmail "Show original", Klaviyo source, any MIME body
Entire email file including headers (From, To, Subject, Content-Type) and multipart bodies. EmailQA parses the message and extracts the HTML part.
From: [email protected] Subject: Welcome Content-Type: text/html <html>...</html>
Common source: Exported .eml from Apple Mail, Thunderbird, Outlook
HTML returned by ESP APIs or webhooks as a JSON string. EmailQA finds the html / body / content field automatically.
{"html": "<html>...</html>", "subject": "Welcome"}Common source: Klaviyo API, Mailchimp render API, webhook payloads
Long blocks of A–Z, a–z, 0–9 and =. Common inside MIME when 8-bit encoding isn't available.
PGh0bWw+PGJvZHk+SGVsbG8gd29ybGQ8L2JvZHk+PC9odG1sPg==
Common source: Multipart MIME attachments, some ESP exports
HTML where every tag is escaped as <div> instead of <div>. Looks like raw angle-bracket gibberish in any browser.
<h1>Welcome</h1><p>Your order is ready.</p>
Common source: Source pulled from inside a textarea, copy/paste from inspectors
HTML where spaces, tags and special characters are replaced with %20, %3C, %3E percent escapes.
%3Chtml%3E%3Cbody%3EHello%20world%3C%2Fbody%3E%3C%2Fhtml%3E
Common source: Query strings, some webhook debug tools, copied URLs
Drop in raw .eml contents, Gmail "Show original" output, JSON responses, or any HTML-like text. No format-picking required.
Detectors run in order of specificity — MIME headers, JSON wrappers, entity escapes, URL encoding, base64, and quoted-printable — and decode the source in one pass.
You see the email exactly as a subscriber would. From there, run real-device rendering, share a preview link, or leave pin-based comments.
If your job involves looking at email source for any reason, this saves you the manual decode step.
Gmail's "Show original" dumps the full MIME source with quoted-printable encoding. Paste it directly — no manual decoding step.
Klaviyo, Mailchimp and HubSpot often transform your template at send time (merge tags, tracking pixels, link rewriting). Preview the actual delivered HTML, not just the source in your builder.
Deliverability tools return the raw message. EmailQA renders it so you can see what the spam filter or recipient would have seen.
Template variables like {{first_name}} only resolve in production. Paste a real send's source to see the final rendered output.
Klaviyo's render API returns JSON with an html field. EmailQA detects the wrapper and extracts the HTML automatically.
Forwarded .eml files from support tickets or compliance reviews render instantly. No command-line mime-parsing tools required.
Litmus, Email on Acid, and Stripo all require pre-decoded HTML input. If you have anything else, you need to run it through a decoder first. EmailQA skips that step.
Other tools can absolutely preview clean HTML — they just don't auto-decode raw email source. Based on documented feature sets as of 2026.
Most email preview tools only accept clean HTML. When you paste raw email source — like the output of Gmail's "Show original" — it contains quoted-printable encoding (=3D, =E2=80=87), MIME headers, or base64 bodies that a browser renders literally instead of decoding. EmailQA detects the format automatically and decodes it before rendering, so you always see the final email instead of the raw source.
Quoted-printable (QP) is a MIME encoding that represents 8-bit characters using =XX hex sequences and breaks long lines with =\r\n soft wraps. It's the default encoding for most email service providers because it keeps emails compatible with older mail servers that only handle 7-bit ASCII. If your email includes any non-ASCII characters (em dashes, emoji, smart quotes, accented letters), it will almost certainly be quoted-printable encoded by the time it hits a recipient.
Yes. Paste the full contents of a .eml file — headers and all — and EmailQA parses it as a MIME message, extracts the HTML part (falling back to plain text if no HTML is present), and renders it. You don't need to manually strip headers or identify the body.
EmailQA auto-detects and decodes seven formats: plain HTML, quoted-printable, base64, raw MIME / .eml messages, JSON-wrapped HTML (common in ESP APIs), HTML-entity-escaped content, and URL-encoded content. Detection runs in order of specificity — strong signals like MIME headers or dense =XX escapes are checked first, so clean HTML never triggers a false-positive decode.
Yes. Klaviyo's rendered email source is quoted-printable encoded, which EmailQA decodes automatically. If you're pulling HTML from the Klaviyo render API, the response is JSON-wrapped — EmailQA handles that too by extracting the html field before rendering.
Yes. "Show original" returns the full raw MIME message — headers, multipart boundaries, quoted-printable body. Paste the entire output directly into EmailQA and it will parse the MIME structure, find the HTML part, and decode the quoted-printable body in one step.
EmailQA renders emails in a sandboxed preview environment that does not fire tracking pixels, send click events, or resolve unsubscribe links during preview. The source is stored privately in your project and is only visible to you and people you explicitly share a preview link with.
Nothing extra — EmailQA checks for strong format signals before attempting to decode. Clean HTML falls through all the detectors and renders normally, so there's no risk of a detector incorrectly decoding a valid HTML email.
Yes. After you paste, EmailQA surfaces a toast notification telling you which format was detected and decoded — for example "Detected quoted-printable email source — decoded automatically." This confirms the decode happened and helps you verify the right format was picked.
Yes. Once your email source is decoded and rendered, you can trigger real-device rendering across Gmail, Outlook, Apple Mail in Light and Dark Mode — all the standard EmailQA testing tools work on the decoded email just like they would on any HTML you upload directly.
Test decoded emails on Gmail, Outlook, Apple Mail
How emails break in Dark Mode
Import Klaviyo source directly
Preview Mailchimp campaigns
Rendering + decoding at 90% less
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