Free online email tools
Email signature generators, DKIM/SPF validators, email template builders, and deliverability checkers.
Three tools for the part of email that happens before you press send, and none of them can send anything — there is no mailbox connection, no SMTP and no credential field anywhere in the hub. Email Signature builds the block that goes under your name: five layouts — corporate, creative, minimal, social and photo — an accent colour picked from ten presets or a custom value, a font choice, an optional headshot or company logo, and links to the profiles you actually use. It gives you two ways out: a rich copy that puts the formatted block on the clipboard as text/html, sanitised through DOMPurify first, and a plain Copy HTML button for the source when you are pasting into a template rather than a settings pane. It also prints the exact settings path for Gmail, Outlook and Apple Mail so you are not hunting through menus. Email Template is a block-based builder for the message itself: stack header, text, image, button, divider and footer blocks in any order, start from a gallery template such as a newsletter, a welcome message or an event invitation, keep merge placeholders like the unsubscribe URL in the footer where they belong, and export both a standalone HTML file and a JSON copy of the project so the layout can be reloaded and edited later rather than rebuilt. Email Preview is where those two meet reality. Paste any HTML and it renders inside stylised Gmail, Outlook and Apple Mail frames at 600 pixels for desktop and 375 for mobile, the two widths that decide most layouts. Alongside the render it runs a heuristic spam score over your markup, weighting the structural problems heaviest: a script tag scores badly because every client strips it, an external stylesheet is flagged because most clients ignore it, and the familiar trigger phrasing and shouty formatting habits are counted too. It lists every link with a warning on any still using plain http rather than https, and checks images for missing alt attributes, which is both an accessibility failure and a real problem in the many clients that block images by default.
3 tools · always free · no account needed
Email Signature
Generate HTML email signatures
Email Preview
Preview HTML emails in desktop and mobile
Email Template
Build HTML email templates with customizable design
How to choose the right tool
Go in the order the work happens. Email Template is where a campaign starts, because a block builder produces the table-and-inline-style HTML that mail clients still require, which hand-writing modern CSS will not. Keep its JSON export alongside the HTML — that is the file that lets you edit the layout next quarter instead of rebuilding it. Take the HTML into Email Preview next, and look hardest at the Outlook frame, since Outlook on Windows renders with Word's layout engine and drops much of what a browser handles without complaint; check the mobile width too, because a 600-pixel table that looks fine on a desktop can force horizontal scrolling on a phone. The spam score belongs to the same pass: it will catch a stray script tag or an external stylesheet before a filter does. Email Signature stands apart from the campaign work entirely. It is a one-off you paste into your client's settings and then forget about, and the moment to open it is when your job title or phone number changes, not when a send goes out.
Frequently asked questions
Why does my email look different in Outlook than in Gmail?
Because Outlook on Windows renders HTML with Microsoft Word's layout engine rather than a browser engine. Float and flexbox are unsupported, background images on most elements are ignored, padding on divs behaves unpredictably, and rounded corners and modern CSS simply do not apply. Gmail strips style tags and the head, forcing everything inline, and clips long messages behind a trim link. Apple Mail is closest to a real browser. That is why email HTML still uses nested tables with inline styles, and why previewing the same file in all three frames is worth the minute it takes.
Is the spam score the same one my email service uses?
No. Real filtering combines sender reputation, authentication records — SPF, DKIM and DMARC — engagement history for your domain, content analysis and recipient behaviour, and most of those live entirely outside the message. This score reads only the HTML you paste and flags specific structural problems: script tags that every client removes, external stylesheets that most ignore, and text and formatting patterns that correlate with junk. Treat it as a checklist for fixing the message, not as a prediction of the inbox. Getting your authentication records right matters far more than any content tweak.
How do I install the generated signature in Gmail or Outlook?
Use the rich copy button, which places the formatted block on the clipboard, then paste it into the client's own signature field: in Gmail that is Settings, then General, then Signature; in Outlook on the web it is Settings, Mail, Compose and reply, Email signature; in Apple Mail it is Preferences, then Signatures, with the use-default-font box unticked so the formatting survives. Pasting the formatted block preserves the inline styles; the separate Copy HTML button is for when you want the source instead. Any logo or headshot must live at a public URL, because an image referenced from your own disk will not load for the recipient.
Does anything I paste here get sent to a server?
No. All three tools work on strings in this tab. The signature builder concatenates HTML and sanitises it with DOMPurify before rendering the preview or writing it to the clipboard; the preview tool parses your markup and applies its scoring and link rules in JavaScript; the template builder serialises blocks to HTML and JSON and downloads them as Blobs. There is no upload, no account, no draft storage and no mail sending anywhere in the hub. It also means nothing is kept for you: download or copy before you close the tab.
What is the JSON export from the template builder for?
Reopening the layout. The HTML export is the finished message you paste into a sending platform, but it is flattened — tables and inline styles — and painful to restructure by hand. The JSON file holds the blocks and their configuration as data, so you can load it back and move, edit or delete sections as blocks again. Keep both files together: the HTML for sending, the JSON as the editable source. It is the difference between a template you can iterate on for a year and one you rebuild from scratch each time.
Why are alt attributes and https links flagged on my images and buttons?
Both fail in the inbox rather than in a browser. Many clients block remote images until the reader clicks to show them, so until that click your alt text is the only thing visible where a hero image or a logo should be — a missing one leaves a blank rectangle and a header with no words in it. Plain http links are flagged because some clients and corporate gateways rewrite, warn on, or refuse to follow them, and because any tracking parameter you attach travels unencrypted. Both are one-line fixes that materially change how the message lands.
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