Prevent Asset Transforms from scaling Image past 100% There is almost never a reason why I would want an image to be scaled past 100% by a transform. This usually results in an image being looking worse than it would if scaled by the browser. Is there a way to tell Craft not to scale an image past 100% of its original size, even if the transform width is larger?
Yes.

getWidth will give you an image's width: {% set originalWidth = image.getWidth(false) %}. You want to apply the transform if desiredWidth is less than originalWidth. I would write a twig macro:

{% macro transform(image, desiredWidth) %}
  {% set originalWidth = image.getWidth(false) %}
  {% if desiredWidth &lt; originalWidth %}
    {{ image.getUrl({mode: 'fit', width: desiredWidth}) }}
  {% else %}
    {{ image.getUrl() }}
  {% endif %}
{% endmacro %}


You could also do the same test, and then conditionally setTransform on the image.

If you define your transforms in the CP the macro would be like this:

{% macro transform(image, transformHandle) %}
  {% set originalWidth = image.getWidth(false) %}
  {% set transformedWidth = image.getWidth(transformHandle) %}
  {% if transformedWidth &lt; originalWidth %}
    {{ image.getUrl(transformHandle) }}
  {% else %}
    {{ image.getUrl() }}
  {% endif %}
{% endmacro %}