Paste your HTML.
Drop in your email HTML or load a sample. It renders in two sandboxed previews and runs the linter — all in your browser, nothing uploaded.
Free tool · runs in your browser
Free Dark Mode Email Tester — catch what dark mode breaks
Preview your email in light and simulated dark mode side by side — and get a checklist of the exact dark-mode bugs that make emails look broken.
Runs in your browser · nothing uploaded · no signupThe dark preview is an approximation of how clients force emails dark — real clients vary, so use it to spot obvious breakage, not for pixel proofing. The linter is the reliable part: every check maps to a documented client dark-mode behavior.
Dark-mode safety
What the Dark Mode Email Tester checks
Eight checks drawn straight from EmailTemple’s dark-mode spec — the rules that decide whether an email survives Gmail, Outlook and Apple Mail forcing it dark.
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Backgrounds
Backgrounds set twice
Warns when a colored zone sets bgcolor or inline background, but not both — clients that force-recolor respect one or the other.
Pure-white surfaces
Flags #ffffff backgrounds that invert to a harsh extreme; suggests a near-white like #f4f4f7.
Pure-black surfaces
Flags #000000 backgrounds that crush hierarchy; suggests a near-black instead.
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Text and contrast
Pure-white body text
Flags #ffffff body copy that is harsh on dark backgrounds; suggests #e0e0e0–#f2f2f2.
color-scheme meta
Checks for the color-scheme meta so clients apply dark mode predictably instead of guessing.
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Images and overrides
Disappearing logo
Flags a masthead image whose cell has no explicit background — a dark logo on transparent can vanish in forced-dark.
Dark-mode overrides
Notes whether you ship prefers-color-scheme rules, and reminds you the Gmail app strips <style>.
Bright image rectangles
Points out that clients never invert images, so bright-background images can punch holes in a dark email.
How it works
Preview, compare, fix the dark-mode bugs.
Compare light and dark.
See the email as authored beside a simulated dark mode. Toggle mobile or desktop width, and turn on aggressive invert to approximate Gmail and Outlook forced-dark.
Fix the findings.
The linter lists the exact dark-mode bugs — set backgrounds twice, avoid pure black and white, add a color-scheme meta — each with how to fix it.
Questions
The Dark Mode Email Tester, in plain language.
Why does my email look broken in dark mode?
Usually because a client forced its colors dark and something did not survive it — a background set only one way, pure black or white surfaces, or a logo on a transparent cell. The linter flags each of these so you can set them before you send.
Why did my logo disappear in dark mode?
A dark logo on a transparent background blends into the surrounding surface when a client forces it dark. Give the logo’s table cell an explicit bgcolor so it keeps a stable backdrop no matter what the client does.
Do email clients really recolor my email?
Yes. The Gmail app, Outlook and some webmail clients apply their own forced-dark treatment — remapping backgrounds and text — and each does it differently. That is exactly why an email needs to be built to survive inversion.
Is this an exact preview of Outlook or Gmail dark mode?
No. The dark preview is a documented approximation of client forced-dark, clearly labeled as such — real clients vary. Use it to spot obvious breakage, not for pixel proofing. The linter is the reliable part.
How do I make an email dark-mode safe?
Set every colored background twice (bgcolor plus inline background-color), avoid pure #ffffff and #000000, give the logo cell an explicit background, and add a color-scheme meta. EmailTemple applies all of this automatically on every generation.
Is my HTML private?
Yes. Both the preview and the linter run in your browser. Your HTML is never uploaded or stored.
Skip the guesswork
Or generate email that’s dark-mode safe by default.
EmailTemple builds every template to survive forced-dark — backgrounds set twice, no pure black or white, a stable logo backdrop — from a single sentence.