Input Mask


Oct 26, 2016
Mar 28, 2019
Redmadrobot (RedMadRobot)
Tobias Preuss (johnjohndoe)
Egor Taflanidi (taflanidi)
Source code
APK file


More GIFs [~3 MB]


Input Mask is an Android & iOS native library allowing to format user input on the fly.

The library provides you with a text field listener; when attached, it puts separators into the text while user types it in, and gets rid of unwanted symbols, all according to custom predefined pattern.

This allows to reformat whole strings pasted from the clipboard, e.g. turning pasted 8 800 123-45-67 into8 (800) 123 45 67.

Each pattern allows to extract valuable symbols from the entered text, returning you the immediate result with the text field listener's callback when the text changes. Such that, you'll be able to extract 1234567 from 8 (800) 123 45 67 or 19991234567 from 1 (999) 123 45 67 with two different patterns.

All separators and valuable symbol placeholders have their own syntax. We call such patterns "masks".

Mask examples:

  1. International phone numbers: +1 ([000]) [000] [00] [00]
  2. Local phone numbers: ([000]) [000]-[00]-[00]
  3. Names: [A][-----------------------------------------------------]
  4. Text: [A…]
  5. Dates: [00]{.}[00]{.}[9900]
  6. Serial numbers: [AA]-[00000099]
  7. IPv4: [099]{.}[099]{.}[099]{.}[099]
  8. Visa card numbers: [0000] [0000] [0000] [0000]
  9. MM/YY: [00]{/}[00]

Questions & Issues

Check out our wiki for further reading. Please also take a closer look at our Known issues section before you incorporate our library into your project.

For your bugreports and feature requests please file new issues as usually.

Should you have any questions, search for closed issues or open new ones at StackOverflow with the input-mask tag.

We also have a community-driven cookbook of recipes, be sure to check it out, too.



Make sure you've added Kotlin support to your project.

repositories {

dependencies {
    implementation 'com.redmadrobot:inputmask:4.0.0'
    implementation 'org.jetbrains.kotlin:kotlin-stdlib:$latest_version'

Known issues

InputMask vs. NoClassDefFoundError

java.lang.NoClassDefFoundError: Failed resolution of: Lkotlin/jvm/internal/Intrinsics;

Receiving this error might mean you haven't configured Kotlin for your Java only project. Consider explicitly adding the following to the list of your project dependencies:

implementation 'org.jetbrains.kotlin:kotlin-stdlib:$latest_version'

— where latest_version is the current version of kotlin-stdlib.

InputMask vs. android:inputType and IndexOutOfBoundsException

Be careful when specifying field's android:inputType. The library uses native Editable variable received on afterTextChange event in order to replace text efficiently. Because of that, field's inputType is actually considered when the library is trying to mutate the text.

For instance, having a field with android:inputType="numeric", you cannot put spaces and dashes into the mentioned Editable variable by default. Doing so will cause an out of range exception when the MaskedTextChangedListener will try to reposition the cursor.

Still, you may use a workaround by putting the android:digits value beside your android:inputType; there, you should specify all the acceptable symbols:

    android:digits="0123456789 -."
    ... />

— such that, you'll have the SDK satisfied.

Alternatively, if you are using a programmatic approach without XML files, you may consider configuring a KeyListener like this:

editText.setKeyListener(DigitsKeyListener.getInstance("0123456789 -.")); // modify character set for your case, e.g. add "+()"

InputMask vs. autocorrection & prediction

(presumably fixed by PR50)


  • You've got a wildcard template like [________], allowing user to write any kind of symbols;
  • Cursor jumps to the beginning of the line or to some random position while user input.

In this case text autocorrection & prediction might be a root cause of your problem, as it behaves somewhat weirdly in case when field listener tries to change the text during user input.

If so, consider disabling text suggestions by using corresponding input type:

    android:inputType="textNoSuggestions" />

Additionally be aware that some of the third-party keyboards ignore textNoSuggestions setting; the recommendation is to use an extra workaround by setting the inputType to textVisiblePassword.


The list of projects that are using this library which were kind enough to share that information.

Feel free to add yours below.

Special thanks

These folks rock:


The library is distributed under the MIT LICENSE.