spaceless
Warning
The spaceless filter is deprecated as of Twig 3.12. While not a full
replacement, you can check the whitespace control features.
Use the spaceless filter to remove whitespace between HTML tags, not
whitespace within HTML tags or whitespace in plain text:
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{{
"<div>
<strong>foo</strong>
</div>
"|spaceless }}
{# output will be <div><strong>foo</strong></div> #}You can combine spaceless with the apply tag to apply the transformation
on large amounts of HTML:
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{% apply spaceless %}
<div>
<strong>foo</strong>
</div>
{% endapply %}
{# output will be <div><strong>foo</strong></div> #}This tag is not meant to "optimize" the size of the generated HTML content but merely to avoid extra whitespace between HTML tags to avoid browser rendering quirks under some circumstances.
Caution
As the filter uses a regular expression behind the scenes, its performance is directly related to the text size you are working on (remember that filters are executed at runtime).
Tip
If you want to optimize the size of the generated HTML content, gzip compress the output instead.
Tip
If you want to create a tag that actually removes all extra whitespace in
an HTML string, be warned that this is not as easy as it seems to be
(think of textarea or pre tags for instance). Using a third-party
library like Tidy is probably a better idea.
Tip
For more information on whitespace control, read the dedicated section of the documentation and learn how you can also use the whitespace control modifier on your tags.