SeeClient-side validation andrangeUnderflow for more information.

For the<meter> element, themin attribute defines the lower numeric bound of the measured range. This must be less than the maximum value (max attribute), if specified. In both cases, if omitted, the value defaults to 1.

The value ofmin andstep define what are valid values, even if thestep attribute is not included, asstep defaults to0.

We add a big red border around invalid inputs:

input:invalid {  border: solid red 3px;}

Then define an input with a minimum value of 7.2, omitting the step attribute, wherein it defaults to 1.

<input name="myNumber" type="number" min="7.2" value="8" />

Becausestep defaults to 1, valid values include7.2,8.2,9.2, and so on. The value 8 is not valid. As we included an invalid value, supporting browsers will show the value as invalid.

If not explicitly included,step defaults to 1 fornumber andrange, and 1 unit type (second, week, month, day) for the date/time input types.

Provide instructions to help users understand how to complete the form and use individual form controls. Indicate any required and optional input, data formats, and other relevant information. When using themin attribute, ensure this minimum requirement is understood by the user. Providing instructions within the<label> may be sufficient. If providing instructions outside of labels, which allows more flexible positioning and design, consider usingaria-labelledby oraria-describedby.

• step
• max
• other meter attributes:low,high,optimum
• Constraint validation
• Form validation
• validityState.rangeUnderflow
• :out-of-range
• <input>
• date,month,week,time,datetime-local,number andrange types, and the<meter>