Ask only for what is needed.
Do not request information the system already has or does not use.
How users enter information.
First, ask yourself
“Can users of your system enter information quickly and correctly the first time?”
Mission statement
Ensure users provide information with minimal effort and error by shaping input around what they know and how they express it.
Key heuristics Input
- Users must not be asked for information the system already has.
- Input formats must accept how users naturally express values.
- Constraints must be visible before input, not discovered after.
- Validation must occur as early as possible without interrupting entry.
- Errors must be indicated at the field where they occur.
- The input method must match the type of data.
- Entered data must survive errors and interruptions.
- Required and optional input must be clearly distinguished.
- Input effort must match the value of the information to the user.
Executive brief
The system must accept input in the form users have it, not in the form the system stores it.
Core questions Input
“Does the system ask only for what it needs, in a form users can provide?”
“Can users enter information correctly without trial and error?”
Focus areas
Effort-first
“What is asked that the system could infer or already knows?”
“How many steps does one piece of information take?”
Format-aware
“Does the field accept common formats?”
“Are constraints shown before entry?”
Error-aware
“When is invalid input detected?”
“Is entered data kept after an error?”
AI-aware
“Is predicted input distinguishable from what users typed?”
“Can users reject autofill easily?”
UX directives Input
Accept natural formats.
Parse common ways users express dates, numbers, names, and addresses.
Show constraints before entry.
State limits, formats, and requirements before users type.
Validate early without interrupting.
Check input as it is completed, not on submission and not on every keystroke.
Locate errors at their source.
Indicate the exact field and the correction needed.
Match the control to the data.
Use the input method that fits the type, range, and frequency of the value.
Preserve entered data.
Keep all valid input through errors, navigation, and interruptions.
Distinguish required from optional.
Mark which input is needed to proceed.
Separate suggested input from entered input.
Make autofill and predictions visible as suggestions until users accept them.
Executive summary
- Input is the user’s transfer of information to the system, not form filling.
- It succeeds or fails on effort and first-time accuracy.
- The system must ask only for what it needs and accept it in natural formats.
- Constraints must be visible before entry, and errors located at their source.
- Entered data must never be lost to an error or interruption.
- Input succeeds when users provide correct information once, without guessing the system’s rules.
Success indicators
- Users are not asked for information the system already has.
- Common formats are accepted without correction.
- Constraints are visible before typing.
- Errors point to the field and the fix.
- Entered data survives errors and interruptions.
One-line summary
Before the system can act on information, users must be able to give it without friction.