Editor configuration

How to change image upload behavior?

The default SidePanel Component has Upload tab to import local images into the project. By default polotno just converting local file into base64 string. Resulted URL strings are using for image elements. Using base64 string may produce projects with a large size, since images will be fully encoded inside JSON.

It is highly recommended to upload images to your server. This will make JSON much smaller and easier to read, and also significantly improve the performance of the editor.

If you want to upload local images to your server you can do this:

import { setUploadFunc } from 'polotno/config';

// define our upload function
// you have to write your own logic, that fits your API
async function upload(localFile) {
  const formData = new FormData();
  formData.append('files[]', localFile);
  const res = await fetch(yourServerURL, {
    method: 'POST',
    body: formData,
  const json = await res.json();
  const { url } = json;
  // return simple and short url
  return url;

// set new function

How to translate UI?

If you want to translate UI into a different language or change some labels you can use this:

import { setTranslations } from 'polotno/config';
  sidePanel: {
    text: 'Текст',
    myFonts: 'Мои шрифты',

If you need to know full scheme of translation object you can use:

import { getTranslations } from 'polotno/config';

// log full translations object

If you are working on a translation for any language or just changing default labels, please share your results with on discord community. It will help us make better defaults for UI and to make ready-to-use translations (thank you!).

Also you can use the same translation API to translate your custom components.

import { observer } from 'mobx-react-lite';
import { t } from 'polotno/utils/l10n';

// in your component
const App = observer(() => {
  return <div>{t('sidePanel.yourLabel')}</div>; // sidePanel.yourLabel is a key in translations object

How to change available fonts?

There are three types of fonts in Polotno:

  1. Google fonts

  2. User fonts defined in store.fonts

  3. Global fonts

1. Google fonts usage

In the default text toolbar, Polotno is using a very large list of google fonts. If you don't want to enable the full list or if you want to disable it you can use this:

import { setGoogleFonts } from 'polotno/config';
// pass an array with google fonts names
// pass empty array if you don't want to see google fonts in available fonts

// restore default loading of google fonts using Polotno API

By default Polotno will load regular, italic, bold and bold italic styles from the font. If you want to customize this and change default styles you can use this:

import { setGoogleFontsVariants } from 'polotno/config';

// default is

// load only regular and thin styles

2. User fonts

If you want to add/remove fonts specific for the user you can use Store Fonts API.

Fonts added into store directly will be included into JSON export via store.toJSON().

A user can add/remove fonts from the default "Text" side-panel inside "fonts" tab.

3. Global fonts

If you want to add fonts that you want to enable for all users you can use global API. Fonts added via global API will be NOT added into JSON export.

import { addGlobalFont } from 'polotno/config';

// add font by its URL
  fontFamily: 'MyCustomFont',
  url: url,

// more control over fonts
  fontFamily: 'MyCustomFont',
  styles: [
      src: 'url(pathToNormalFile.ttf)',
      fontStyle: 'normal',
      fontWeight: 'normal',
      src: 'url(pathToBoldFile.ttf)',
      fontStyle: 'normal',
      fontWeight: 'bold',

// if a font is already added into the page by some CSS
// you can register it inside polotno
// so it can be listed in available fonts in the toolbar

  fontFamily: 'MyCustomFont',

Hot to get API endpoints to get a list of available google fonts?

import { getGoogleFontsListAPI, getGoogleFontImage } from 'polotno/config';

// returns an URL to api.polotno.com
const url = getGoogleFontsListAPI();
// when you fetch the list you can show preview of every font in the list
// to get image path you can use this:
<img src={getGoogleFontImage('Roboto')} />;

Change default preset colors in color picker

By default color picker generates preset colors from (1) used colors in the design and (2) default colors. You can change your logic with your own presets

import { setColorsPresetFunc } from 'polotno/config';

// define your own function
setColorsPresetFunc((store) => {
  // return array of colors
  return ['#000', '#fff'];

News, updates and promos – be the first to get 'em

News, updates and promos – be the first to get 'em