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MJML.ai Use Case

MJML Validator for production-safe email templates

Use this workflow when your template mostly works but you need confidence before sending. Validate tag nesting, layout structure, and output quality so broken markup does not reach subscribers.

Catch structural issues early

Spot invalid nesting, unsupported combinations, and malformed sections before they become delivery-time surprises.

Reduce QA cycles

Validate once in a focused pass instead of discovering errors late in a fragmented render-test loop.

Ship with confidence

Pair validation with compile preview so your final HTML is reliable across major clients.

When to use MJML Validator

  • You inherited a template and need a quick safety check before campaign launch.
  • You are iterating on modular sections and want to confirm each update remains valid.
  • You need a repeatable final pass before handing templates to marketing or lifecycle teams.

Practical checks

Common MJML errors worth catching

Invalid nesting

Components such as mj-column placed outside the mj-section structure they require.

Missing attributes

Buttons, images, or links without the values needed to compile or behave correctly.

Unsupported components

Misspelled tags or components that are unavailable in the selected MJML version.

Risky output

Markup that compiles but still needs desktop, mobile, and inbox-client review.

Example

From validation error to valid structure

Invalid

<mj-body>
  <mj-column>...</mj-column>
</mj-body>

Valid

<mj-section>
  <mj-column>...</mj-column>
</mj-section>

Related workflows

Validation catches issues. Repair fixes them. Conversion workflows help migrate old assets.