8 Best Free and Open-Source JavaScript Image Editors

The internet is filled with countless images uploaded by users. This is especially true for social media websites—and it is very rare for people to post original unedited images anywhere. It is also common to need to post images with a specific size or format. While there are a lot of full-fledged image editing apps on smartphones today, it can still be a bit inconvenient for people to crop or resize any images before uploading them.

Luckily, JavaScript has a lot of free and open-source libraries that can help you do some basic as well as fairly advanced image editing. Use them in your own projects to give users the option to crop or scale any image after they upload it.

In this post, we will give you a brief overview of the best free and open-source JavaScript image editors that you can add to your website today.

Filerobot Image Editor

Filerobot is one of the most feature-rich free JavaScript image editors that you will find. It comes with tonnes of image manipulation features. You can easily adjust the brightness, contrast, saturation and exposure of the images. There are also some built-in effects and filters in case you want something that will give you results similar to Instagram filters.

You can easily change the rotation of an image or flip it horizontally and vertically. The images can be easily cropped to some preset aspect ratios like banners and squares etc. There is also an option to specify a custom width and height for the images.

The editor comes with the ability to add your own branding over the images you edit with custom watermarks as well as text and shape overlays. There are two available themes called light and dark but you can create your own themes to match the color scheme of the website where you plan to integrate the editor.

You can try out all the features of the editor on the demo page. It comes in two versions: vanilla JS and React component. Integrations with other libraries and frameworks are also planned in the future.

CamanJS

CamanJS is yet another popular JavaScript based image editor that comes with a decent feature set. The library has not been updated for a while now which means that it won't add any new features. However, you can still use it to do plenty of tasks.

It comes with a large variety of methods to adjust the brightness, contrast, saturation, vibrance, sharpness, noise and many other things. There are a lot of Instagram-inspired and original preset filters available for you to use as well and the effect they produce is pretty amazing. You can also create multiple layers and apply blend modes to them in order to create something more complex.

You also have the option to apply different filters to image elements on a webpage by using the data-caman attribute. The filters will then be applied automatically to images on page load.

The thing that I like most about the library is its ease of extensibility and the control the library gives to its users. It is possible for you to register your own filters and blend modes with the library to apply directly to different images. You can also track the filter progress by listening to different events fired by CamanJS. Our series on creating an image editor with CamanJS covers all aspects of the library in great detail.

Toast UI Image Editor

Toast UI Image editor is also a full-fledged and free image editor that comes in three flavors. You can either use the vanilla JavaScript version or go with the Vue or React wrapper components.

It comes with its own UI but you get the option to use the API directly to edit the images. There are light and dark themes in the editor and you can choose whether to place the image editing controls on the left, right, top or bottom side.

Users can crop, flip and rotate the image once it has loaded into the editor. They can also draw over the image with straight lines or freestyle. Some predefined shapes and icons can be layered on the top of main image as well. Common editing options like brightness, grayscale, pixelation and inversion are also available. However, you cannot change the contrast or saturation of the image which could be a bummer.

Lena.js

Lena.js is an easy-to-use lightweight library for image processing. The difference between Lena.js and other libraries is that it does not give you granular control over the image editing process. There are some common predefined filters that you can apply to your images.

The filters are primarily divided in two categories. First are pixel to pixel filters for changing saturation or making images grayscale. The other category includes edge detection filters. You can check out all of them in action on the demo page of the library.

VintageJS

The VintageJS library does exactly what its name suggests. It allows you to apply some amazing vintage effects over images. You just need to pass your source and an object with all the filter options as parameters to the vintagejs function.

The flexibility in the use of this library comes from the fact that the source can be a path to an actual image as well as an image or canvas element on the webpage. The function then returns a promise which resolves to a result object. The result object also has three methods to help you to get the data URL of the updated image, the canvas element or an image element with the updated image data.

Try out the demo of the library to see if you like these vintage effects.

Filterous 2

The Filterous 2 library is yet another great option for people who just want a library to quickly apply some popular and well known preset effects on images. It comes with around 40 different Instagram inspired filters to apply on your images.

Other than that, it also gives you the option to apply some basic effects like increasing or decreasing the brightness, contrast and saturation of images by passing a value between -1 and 1. You can also apply effects like blurring, sharpening and edge detection to images by using a convolution matrix.

Image Editors Based on WebGL

All the libraries that I have mentioned so far run all the image manipulation code on CPU. This is not a problem when you are editing small images or when users don't mind waiting for a bit in order to see the final results. However, it is not possible for a CPU to show real-time results when it has to do all these calculations for millions of pixels.

This is where WebGL proves to be very helpful. You can use some WebGL-based libraries to do all the calculations for image editing on a GPU. The parallelization of all that pixel color computation in a GPU means that any effects the you apply on images will show up instantly.

Glfx.js

The first library that I would like to talk about in this category is Glfx.js. It gives you access to all the functions that you need to adjust the brightness, contrast, hue, saturation, vibrance and noise in an image.

It also supports 4 different blurring methods. This includes zoom blur, lens blur and tilt shift in addition to uniform blurring of the whole image. There are some additional effects included in the library like a grayscale or color halftone that gives images a comic-like look. You can also distort the images using a bunch of warping filters that can create a bulging, swirling or perspective changing effect.

Not all filters and effects will give good results on every image. For example, the lens blur effect looks great only if there are some bright point light sources in the image. You can see how quickly filters are applied on an image with this library in the demo.

Pixelapp

Pixelapp is another image editor that you can use to edit images with WebGL. It gives you the option to adjust the values for brightness, contrast, saturation, shadows, tint, hue and many other properties. All of these effects are divided in four categories called light, color, detail and effects.

It also comes with support for multi-level undo and redo actions in case you are not satisfied with the some of the previous changes you made to an image. There is a divider that you can drag over the image to see the original and edited image side-by-side. You can also flip the image horizontally and vertically or scale as well as rotate it if needed.

Try editing some of your images in the editor. You will be impressed with its speed and functionality.

Final Thoughts

In this post, we have provided you a brief overview of some of the best free and open source JavaScript image editors. Some of them like Filerobot and Toast UI come with their own built-in UI while others like CamanJS give you the flexibility to implement the UI on your own. You should consider using one of the WebGL based editors if you want a library that shows the results in real-time.