See your real email in 50+ email clients and devices, each in light and dark mode: Gmail, Outlook, Apple Mail, iPhone, Android, and more. Run it on its own, no spam test needed: paste your HTML or send us the email, and pixel-accurate screenshots come back in about a minute. The Custom plan adds 13 renders from the newest devices, including iPhone 18 Pro, Pixel 10, and New Outlook for Windows.
Every client renders HTML its own way. Outlook still leans on the Word engine, Gmail strips styles it does not like, Apple Mail honors almost everything. A layout that looks perfect where you built it can fall apart in the client half your list actually opens.
Most readers now open mail in dark mode, where clients invert colors, repaint backgrounds, and can turn a dark logo invisible on a dark panel. You never catch it unless you look at the dark variant of each client.
Checking by hand means a drawer of phones and a stack of email accounts, and you still miss Outlook 2016, older Android builds, and the regional webmail your international readers use. Most teams just send and hope for the best.
Plenty of clients still block remote images until the reader allows them, so what arrives first is your alt text and your background colours. If the message only works once the pictures load, most people never see the version you designed.
See your email exactly as Gmail, Outlook, Apple Mail, Yahoo, and dozens more display it, in both light and dark. Switch clients from one result, with no test accounts to manage and no screenshots to stitch together.
The same render feeds the AI eye-tracking heatmap, so in one result you can confirm the layout holds up and that the eye lands on your offer, across desktop, tablet, and mobile. Warm zones mark where the eye lands first and cool zones what gets skipped, so you can move your headline and CTA to where readers already look.
Paste HTML and run previews on their own, or get them inside the same result as your spam score, authentication checks, and per-provider placement. No second subscription, no context switch.
Each preview is your email opened in an actual copy of the client and device, not a browser mockup, so what you see is what your subscriber sees, dark mode included.
Every plan includes a monthly allowance of device previews, the free tier included, so you can see how your email renders without adding a card.
A single upload renders across the desktop clients, mobile apps, and webmail your list actually opens in, so you are not checking Outlook on Monday and an iPhone on Thursday.
The same upload returns an AI heatmap of where readers look first, so you can tell whether a layout that renders correctly also puts your call to action where attention lands.
There is no drawer of phones and no stack of test accounts to keep alive. The clients run on our side, so widening your coverage is a checkbox rather than a purchase.
Paste the subject line and HTML straight into the form above, or add the Unspam seed address to your campaign and send the exact message you plan to ship. No ESP to connect, no signup needed to try it.
Unspam opens your email in 50+ real clients and devices and captures exactly what each one shows, in both light and dark.
Pick any client from the dropdown to see a pixel-accurate preview. Spot the broken column, the invisible dark-mode logo, or the CTA that gets cut off.
Adjust the HTML, paste or send the new version, and confirm it holds together across every client before the campaign reaches a subscriber.
The moments teams pull up client previews before a send. Run them standalone from pasted HTML, or next to the spam score inside a full test to check rendering and deliverability in one pass.
Before a campaign goes out, walk the preview across Gmail, Outlook, and Apple Mail to confirm the layout, images, and links hold up everywhere your list reads.
Open the dark-mode email preview next to the light one to catch inverted colors, a logo that vanishes on a dark background, or text that drops below readable contrast, before your subscribers see it.
Test a master template once across every client so the structure is sound, then reuse it knowing it renders cleanly on desktop, webmail, and mobile.
When a design breaks only in Outlook, compare the 2016, 2019, and Office 365 renders side by side to find exactly where the Word engine trips.
Confirm a weekly newsletter reads well from a wide desktop screen down to an iPhone SE, where columns stack and the preheader takes the first line.
Open the same email preview with images blocked to see the alt text your reader gets by default, confirm the preheader takes the first line, and make sure the message still reads before a single image loads.
Receipts, password resets, and order confirmations render across just as many clients as a campaign does. Preview the emails your product sends automatically so a broken table or a missing button never reaches a customer mid-flow.
Agencies can show a client precisely how their email will look in every major inbox before approval, instead of promising it will be fine.
One run renders your message everywhere your subscribers read it, from pasted HTML or a real send.
Every run renders an email preview across 50+ real email clients and devices: desktop apps, webmail, and phones, each in light and dark. That includes Gmail, Outlook 2007 through 2019, Outlook.com, Office 365, Apple Mail, iCloud, Yahoo, AOL, GMX, Zoho, Thunderbird, eM Client, and Mailbird, plus iPhone, iPad, and Android. With both modes captured that is more than 100 renders per run, and each one is a real screenshot from the live client, not a browser simulation. A selection of what you get:
Gmail
Outlook
Office 365
Apple Mail
iCloud
Yahoo Mail
AOL
GMX
Zoho Mail
Thunderbird
eM Client
Mailbird
Windows 10 Mail
iPhone iPad
AndroidWhat client previews cover, how they fit the rest of a test, and where they help before a send.
Every test renders your email across 50+ real clients and devices, including Gmail, Outlook (2007 through 2019, plus Outlook.com and Office 365), Apple Mail, iCloud, Yahoo, AOL, GMX, and Zoho, alongside mobile devices like the iPhone, iPad, and Android. Desktop apps, webmail, and phones are all covered, each in light and dark. See the pricing page for how many tests each plan includes.
The Custom plan adds 13 renders from the newest devices: iPhone 18 Pro, the Gmail app on Pixel 10 and iPhone 16, the Outlook Microsoft 365 app on Windows 11 and macOS, and New Outlook for Windows, each in light and dark, plus Gmail web in Chrome in light mode.
No. Unspam renders each preview on its own copy of the client and device, so you do not need a drawer of phones or a pile of email logins. You paste your HTML or send one real email, and every client comes back in the same result.
Yes. Clients that support dark mode are rendered in both light and dark, so you can catch the classic failures: inverted colors, a dark logo that disappears on a dark panel, and text that loses contrast. Dark mode is where a lot of otherwise clean emails break.
It works both ways. Run it standalone: paste HTML on this page and get renders with no other test involved. Or run a spam and placement test and the previews come back next to your spam score, authentication breakdown, and per-provider placement, so you fix how the email looks and whether it reaches the inbox in one pass. There is nothing extra to install and no ESP to connect.
Yes, and it is included on every plan, the free tier included. Each test returns the client previews, the spam score, authentication checks, and the attention heatmap together. Standalone client previews have their own monthly allowance: 3 on the Free plan, with no card required to start, and on the Custom plan you choose the monthly volume yourself.
Two ways. Paste the subject and HTML into the form on this page, or add the Unspam seed address to your campaign and send the real message to it, the same way you send to any subscriber. Unspam never connects to your sending platform, so you always preview the exact email your audience receives. The renders come back in about a minute.
Yes. Paste your HTML straight into the tool and Unspam renders it across every client and device with no send required, which also makes it a quick HTML email tester during development. When you would rather verify the exact production message, use the send option instead.
Paste your HTML or forward the email to your private Unspam address, and pixel-accurate previews of 50+ clients are ready in about a minute. For the full pre-send check, run a spam and placement test on the same message so you verify rendering and inbox placement together.
Yes. Every email preview includes real mobile devices, not just desktop, so you see how the layout reflows on the iPhone, iPad, and Android. Columns stack, tap targets grow, and the preheader takes the first line, exactly as your reader gets it. Pair it with the attention heatmap to confirm the eye still lands on your offer on a small screen.
Each preview is your email opened in an actual copy of the client and device, not a mockup or a browser simulation, so what you see is what your subscriber sees, dark mode included. Run previews inside a full test and they arrive next to your deliverability and spam results, so you confirm how the email looks and whether it reaches the inbox in one pass.
Desktop Outlook renders HTML with the Microsoft Word engine, so layouts that look fine in Gmail or Apple Mail can lose backgrounds, break columns, or misplace spacing there. That is why the previews cover every desktop Outlook from 2007 to 2019 plus Outlook.com and Office 365: you see exactly which version trips and can fix the markup before the send.
Outlook is the client most likely to break an HTML email because it still leans on the Word rendering engine. Unspam renders Outlook 2007 through 2019 plus Outlook.com and Office 365, so you can compare the versions side by side and find exactly where a design trips. Run it as part of an inbox placement test to catch rendering and deliverability issues together.
On the Custom plan the list also includes the Outlook Microsoft 365 app on Windows 11 and macOS and New Outlook for Windows, both in light and dark mode.
Yes. The email preview API returns the same pixel-accurate renders as JSON: create a test via REST, send your email, and read back per-device screenshots for 50+ real clients, with a device filter for CI pipelines. The previews are also exposed as tools on the Unspam MCP server, so AI agents like Claude can run rendering checks in plain language.
Email client testing, also called email rendering testing, means checking how your email displays across the different apps and devices your subscribers use, since each one renders HTML its own way. That is exactly what this does: every email preview is a rendering test across 50+ real clients and devices, in light and dark, so you catch a layout that breaks in Outlook or a dark-mode logo that vanishes before you send. Run it next to a spam and placement test to cover rendering and deliverability in one pass.
Paste your HTML or send one real email and get pixel-accurate previews across 50+ clients, in light and dark mode, back in about a minute. No card, no signup.
