HTML email is the format that time forgot.
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Formats nested table layouts cleanly
Preserves MSO conditional comments
Keeps inline styles intact
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Email HTML has not converged on modern web standards because the rendering surface is fragmented. Gmail, Outlook desktop, Outlook web, Apple Mail, Yahoo Mail, and dozens of native mobile clients each interpret CSS and HTML differently, and many of them lack support for features that have been standard on the web for a decade. The result is a defensive coding style: table-based layouts because flexbox and grid are not reliable, inline styles because external stylesheets are stripped or ignored, MSO conditional comments because Outlook needs special instructions, and a heavy dose of repetition because reusable components cannot rely on the cascade. Formatting tools designed for modern web HTML often mangle these patterns, so email templates need a formatter that understands the conventions.
FixTools formats email HTML by parsing it with a tolerant HTML5 parser that recognises conditional comments as comments rather than trying to evaluate them, preserves table structure with clean depth-based indentation, keeps inline style attributes exactly as supplied even when they span hundreds of characters, and leaves embedded VML markup for Outlook bullet-proof buttons untouched. The output is a faithfully formatted version of the input that you can read, edit, and re-export to your email service provider without any risk of breaking client compatibility. The structural fidelity is the whole point: an email template that worked before formatting must work identically after formatting, in every client, with no exceptions.
Inline styles deserve special mention because they are the dominant styling mechanism in email. A single button element in a formatted email template may carry a style attribute hundreds of characters long, with margins, padding, fonts, colours, borders, and hover behaviours all packed into one attribute. The formatter preserves this exactly without attempting to wrap, break, or normalise the inline style. Breaking the inline style across lines would risk introducing whitespace inside the attribute value that some email clients would render incorrectly, and reformatting the CSS inside the attribute would produce non-deterministic output. The principle is conservative: format the HTML structure aggressively, but treat inline styles as opaque text.
A separate consideration is the MSO conditional comments that target Outlook specifically. These look like HTML comments but contain real markup that Outlook will render. The formatter preserves them as comments without modification, which keeps the Outlook-specific code intact while still allowing the surrounding HTML to be formatted normally. If you need to edit the content inside a conditional, copy it out, edit it as standalone HTML, and paste it back inside the conditional comment. The formatter does not descend into comment contents because doing so would risk reformatting Outlook-specific markup in ways that break in the email client where it matters most.
Paste your email HTML and click Format. The output panel shows the template with clean table indentation, intact conditionals, and preserved inline styles ready for editing or testing.
Step-by-step guide to format html email template:
Export your email template
Export the HTML from your email service provider or copy it from your template repository. Most ESPs offer a download or copy-HTML option in the template editor.
Paste it into FixTools
Paste the exported HTML into the FixTools input panel. The full template including doctype, head, and body sections should be pasted as a single block.
Click Format
Click Format to restore indentation across the table layout while preserving inline styles, conditional comments, and any VML blocks for Outlook compatibility.
Copy and test
Copy the formatted template back to your editor or directly back into your ESP. Run a rendering test in Litmus or Email on Acid to confirm the formatting did not change client behaviour.
Common situations where this approach makes a real difference:
Cleaning up a designer-exported email template
A designer exports an HTML email from a visual builder and hands it to a developer for production. The export is compressed and visually impenetrable. The developer formats it in FixTools, instantly sees the table nesting structure, and identifies two places where the design diverges from the intended responsive behaviour. Fixes that would have taken an hour of careful counting take five minutes once the structure is readable.
Migrating templates between email service providers
A marketing team migrates fifty templates from one email service provider to another. Each source template comes back compressed during export. Formatting them first allows the team to confirm the layout structure, identify any merge tag syntax that needs translation between providers, and document the differences for the migration plan. The formatting step turns a guesswork-heavy migration into a methodical one.
Auditing a transactional email for accessibility
An accessibility audit of a password reset email requires the auditor to verify alt text, heading structure, and link descriptions. The original template is compressed and hard to read. Formatting it first lets the auditor scan the document outline, count headings, and verify alt text in minutes rather than the half hour it would take against the compressed source.
Debugging a broken hero image in Outlook 2016
A campaign renders a hero image incorrectly in Outlook 2016 but correctly everywhere else. The developer formats both the source template and the rendered HTML from Outlook, diffs the two, and discovers that Outlook stripped a width attribute the design relied on. Adding a fallback in an MSO conditional fixes the rendering without affecting any other client.
Use this when you receive a compressed or hand-edited HTML email template and you need readable structure before testing, editing, or sending it for review.
Get better results with these expert suggestions:
Format before sending to a developer for review
When handing an email template to a developer for accessibility review, code audit, or campaign QA, format it first. A formatted template can be reviewed in minutes, while a compressed one requires the reviewer to spend most of their time mentally parsing structure rather than actually evaluating the markup. The reviewer time saved more than justifies the few seconds of formatting effort, and the quality of the review goes up because attention is focused on the meaningful issues rather than on decoding the source.
Format both the source and the rendered output
When debugging why an email looks wrong in a specific client, format both the source template and the rendered HTML captured from the email client. Diffing the two formatted versions reveals exactly what the client modified during rendering, such as injected tracking pixels, stripped style rules, or rewritten link wrappers. This is the fastest way to understand client-specific rendering surprises and to know whether the issue is in your template or in the client behaviour.
Use formatting as a sanity check after merge tag substitution
When testing personalisation tokens or merge tags, format the substituted output to confirm the substitution did not produce malformed HTML. Merge tags that contain unescaped angle brackets or quotation marks frequently produce structural errors that are invisible in the compressed test output but obvious once formatted. Catching these in QA prevents production sends where personalised content breaks the layout for affected recipients.
Keep conditional comments in their canonical Outlook form
When editing inside MSO conditional comments, preserve the exact opening and closing syntax that Outlook expects. The conditionals are not arbitrary HTML comments; they have specific syntax that Outlook recognises. The formatter preserves them correctly, but if you hand-edit them, double-check that the opening and closing match the original pattern. A single misplaced character in a conditional can cause Outlook to render either nothing or the wrong content.
Test in Litmus or Email on Acid after editing
After formatting and editing an email template, send it through a rendering test service to confirm it still displays correctly across all major clients before shipping.
Keep a working copy before formatting
Save the original template as a backup before formatting. Email rendering can be fragile, and having an untouched copy lets you compare or revert if something looks off after formatting.
Avoid reformatting the inline CSS
Format the HTML structure but resist the urge to break inline style attributes across lines. Inline styles need to stay on one line to render reliably in older Outlook versions.
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