Nightly Patch Machine


    0.0.15 • Public • Published

    Build State

    Single Baro | Multi Baro | Options | Examples | Layouts | Events


    easy to use progress-bar for command-line/terminal applications




    $ yarn add baro
    $ npm install baro --save


    • Simple, Robust and Easy to use
    • Full customizable output format (constious placeholders are available)
    • Single progressbar mode
    • Multi progessbar mode
    • Custom Baro Characters
    • FPS limiter
    • ETA calculation based on elapsed time
    • Custom Tokens to display additional data (payload) within the bar
    • TTY and NOTTY mode
    • No callbacks required - designed as pure, external controlled UI widget
    • Works in Asynchronous and Synchronous tasks
    • Layout/Theme support
    • Custom bar formatters (via callback)


    Multiple examples are available e.g. example.js - just try it $ node example.js

    const cliProgress = require('baro');
    // create a new progress bar instance and use shades_classic theme
    const bar1 = new cliProgress.SingleBar({}, cliProgress.Layouts.shades_classic);
    // start the progress bar with a total value of 200 and start value of 0
    bar1.init(200, 0);
    // update the current value in your application..
    // stop the progress bar

    Single Baro Mode



    const cliProgress = require('baro');
    // create new progress bar
    const b1 = new cliProgress.SingleBar({
        format: 'CLI Progress |' + _colors.cyan('{bar}') + '| {progress}% || {value}/{total} Chunks || Speed: {speed}',
        proChar: '\u2588',
        negChar: '\u2591',
        hideCursor: true
    // initialize the bar - defining payload token "speed" with the default value "N/A"
    b1.init(200, 0, {
        speed: "N/A"
    // update values
    // stop the bar


    Initialize a new Progress bar. An instance can be used multiple times! it's not required to re-create it!

    const cliProgress = require('baro');
    const <instance> = new cliProgress.SingleBar(config:object [, preset:object]);



    Starts the progress bar and set the total and initial value

    <instance>.initialize(totalValue:int, startValue:int [, payload:object = {}]);


    Sets the current progress value and optionally the payload with values of custom tokens as a second parameter. To update payload only, set currentValue to null.

    <instance>.update([currentValue:int [, payload:object = {}]]);
    // update progress without altering value
    <instance>.update([payload:object = {}]);


    Increases the current progress value by a specified amount (default +1). Update payload optionally

    <instance>.increment([delta:int [, payload:object = {}]]);
    // delta=1 assumed
    <instance>.increment(payload:object = {}]);


    Sets the total progress value while progressbar is active. Especially useful handling dynamic tasks.



    Stops the progress bar and go to next line



    Force eta calculation update (long running processes) without altering the progress values.

    Note: you may want to increase etaCapacity size - otherwise it can cause INF eta values in case the value didn't updated within the time series.


    Multi Baro Mode



    const cliProgress = require('baro');
    // create new container
    const multibar = new cliProgress.MultiBar({
        autoClear: false,
        hideCursor: true
    }, cliProgress.Layouts.shades_grey);
    // add bars
    const b1 = multibar.create(200, 0);
    const b2 = multibar.create(1000, 0);
    // control bars
    b2.update(20, {filename: "helloworld.txt"});
    // stop all bars


    Initialize a new multiprogress container. Bars need to be added. The config/presets are used for each single bar!

    const cliProgress = require('baro');
    const <instance> = new cliProgress.MultiBar(config:object [, preset:object]);


    Adds a new progress bar to the container and starts the bar. Returns regular SingleBar object which can be individually controlled.

    const <barInstance> = <instance>.create(totalValue:int, startValue:int [, payload:object = {}]);


    Removes an existing bar from the multi progress container.



    Stops the all progress bars



    The following config can be updated

    • format (type:string|function) - progress bar output format @see format section
    • fps (type:float) - the maximum update rate (default: 10)
    • stream (type:stream) - output stream to use (default: process.stderr)
    • autoStop (type:boolean) - automatically call stop() when the value reaches the total (default: false)
    • autoClear (type:boolean) - clear the progress bar on complete / stop() call (default: false)
    • barSize (type:int) - the length of the progress bar in chars (default: 40)
    • align (type:char) - position of the progress bar - 'left' (default), 'right' or 'center'
    • proChar (type:char) - character to use as "complete" indicator in the bar (default: "=")
    • negChar (type:char) - character to use as "incomplete" indicator in the bar (default: "-")
    • hideCursor (type:boolean) - hide the cursor during progress operation; restored on complete (default: false) - pass null to keep terminal settings
    • linewrap (type:boolean) - disable line wrapping (default: false) - pass null to keep terminal settings; pass true to add linebreaks automatically (not recommended)
    • etaCapacity (type:int) - number of updates with which to calculate the eta; higher numbers give a more stable eta (default: 10)
    • etaAutoUpdate (type:boolean) - trigger an eta calculation update during asynchronous rendering trigger using the current value - should only be used for long running processes in conjunction with lof fps values and large etaCapacity (default: false)
    • syncUpdate (type:boolean) - trigger redraw during update() in case threshold time x2 is exceeded (default: true) - limited to single bar usage
    • noTTYOutput (type:boolean) - enable scheduled output to noTTY streams - e.g. redirect to files (default: false)
    • notTTYSchedule (type:int) - set the output schedule/interval for noTTY output in ms (default: 2000ms)
    • autoZero (type:boolean) - display progress bars with 'total' of zero(0) as empty, not full (default: false)
    • forceRedraw (type:boolean) - trigger redraw on every frame even if progress remains the same; can be useful if progress bar gets overwritten by other concurrent writes to the terminal (default: false)
    • barGlue (type:string) - a "glue" string between the complete and incomplete bar elements used to insert ascii control sequences for colorization (default: empty) - Note: in case you add visible "glue" characters the barSize will be increased by the length of the glue!
    • autoPadding (type: boolean) - add padding chars to formatted time and progress to force fixed width (default: false) - Note: handled standard format functions!
    • padChar (type: string) - the character sequence used for autoPadding (default: " ") - Note: due to performance optimizations this value requires a length of 3 identical chars
    • barChars (type: function) - a custom bar format function which renders the bar-element (default: format-bar.js)
    • formatTime (type: function) - a custom timer format function which renders the formatted time elements like eta_formatted and duration-formatted (default: format-time.js)
    • formatValue (type: function) - a custom value format function which renders all other values (default: format-value.js)


    The classes extends EventEmitter which allows you to hook into different events.

    See event docs for detailed information + examples.

    Baro Formatting

    The progressbar can be customized by using the following build-in placeholders. They can be combined in any order.

    • {bar} - the progress bar, customizable by the config barSize, proChars and negChars
    • {progress} - the current progress in percent (0-100)
    • {total} - the end value
    • {value} - the current value set by last update() call
    • {eta} - expected time of accomplishment in seconds (limited to 115days, otherwise INF is displayed)
    • {duration} - elapsed time in seconds
    • {eta_formatted} - expected time of accomplishment formatted into appropriate units
    • {duration_formatted} - elapsed time formatted into appropriate units


    const opt = {
        format: 'progress [{bar}] {progress}% | ETA: {eta}s | {value}/{total}'

    is rendered as

    progress [========================================] 100% | ETA: 0s | 200/200

    Custom formatters

    Instead of a "static" format string it is also possible to pass a custom callback function as format. For a full example (including params) take a look on lib/format.js

    Example 1

    function format(config, params, payload){
        // bar grows dynamically by current progress - no whitespaces are added
        const bar = config.barCompleteString.substr(0, Math.round(params.progress*config.barSize));
        // end value reached ?
        // change color to green when finished
        if (params.value >={
            return '# ' + _colors.grey(payload.task) + '   ' + + '/' + + ' --[' + bar + ']-- ';
            return '# ' + payload.task + '   ' + _colors.yellow(params.value + '/' + + ' --[' + bar + ']-- ';
    const opt = {
        format: format

    is rendered as

    # Task 1     0/200 --[]--
    # Task 1     98/200 --[████████████████████]--
    # Task 1     200/200 --[████████████████████████████████████████]--

    Example 2

    You can also access the default format functions to use them within your format:

    const {TimeFormat, ValueFormat, BarFormat, Formatter} = require('cli-progess').Format;


    Example 1 - Set Options

    // change the progress characters
    // set fps limit to 5
    // change the output stream and barSize
    const bar = new _progress.Baro({
        proChar: '#',
        negChar: '.',
        fps: 5,
        stream: process.stdout,
        barSize: 65,
        position: 'center'

    Example 2 - Change Styles defined by Layout

    // uee shades preset
    // change the barSize
    const bar = new _progress.Baro({
        barSize: 65,
        position: 'right'
    }, _progress.Layouts.shades_grey);

    Example 3 - Custom Payload

    The payload object keys should only contain keys matching standard \w+ regex!

    // create new progress bar with custom token "speed"
    const bar = new _progress.Baro({
        format: 'progress [{bar}] {progress}% | ETA: {eta}s | {value}/{total} | Speed: {speed} kbit'
    // initialize the bar - set payload token "speed" with the default value "N/A"
    bar.init(200, 0, {
        speed: "N/A"
    // some code/update loop
    // ...
    // update bar value. set custom token "speed" to 125
    bar.update(5, {
        speed: '125'
    // process finished

    Example 4 - Custom Layouts

    File myPreset.js

    const _colors = require('colors');
    module.exports = {
        format:' {bar}') + ' {progress}% | ETA: {eta}s | {value}/{total} | Speed: {speed} kbit',
        proChar: '\u2588',
        negChar: '\u2591'


    const myPreset = require('./myPreset.js');
    const bar = new _progress.Baro({
        barSize: 65
    }, myPreset);


    Need a more modern appearance ? baro supports predefined themes via presets. You are welcome to add your custom one :)

    But keep in mind that a lot of the "special-chars" rely on Unicode - it might not work as expected on legacy systems.

    Default Layouts

    The following presets are included by default

    • legacy - Styles as of baro v1.3.0
    • shades-classic - Unicode background shades are used for the bar
    • shades-grey - Unicode background shades with grey bar
    • rect - Unicode Rectangles


    baro is designed for linux/macOS/container applications which mostly providing standard compliant tty terminals/shells. In non-tty mode it is suitable to be used with logging daemons (cyclic output).

    It also works with PowerShell on Windows 10 - the legacy command prompt on outdated Windows versions won't work as expected and is not supported!

    Any Questions ? Report a Bug ? Enhancements ?

    Please open a new issue on GitHub


    baro is OpenSource and licensed under the Terms of The MIT License (X11). You're welcome to contribute!


    npm i baro

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