Convert Images - resize, crop, and change the format of image files using the Filestack v2 library

In addition to uploading files and raw data, the Javascript API can also perform basic conversions on images. This method generates a new filestack link and counts as both an upload and a conversion.


<script src=""></script>
<script type="text/javascript">
  filepicker.convert(Blob, conversion_options, storage_options, onSuccess(Blob){}, onError(FPError){}, onProgress(percent){});

Convert Code Example - Resize image to 200x200

Resize contents of blob to 200x200 and then confirm new image is different
var blob = { url: '', filename: 'robot.png', mimetype: 'image/png', isWriteable: false, size: 28683 }; filepicker.stat( blob, { width: true, height: true }, function(metadata) { console.log("Original image Dimensions:"); console.log(JSON.stringify(metadata)); } ); console.log("Converting..."); /*an <img> element where we can display the resulting image*/ var result = document.getElementById("convert-result"); filepicker.convert( blob, { width: 200, height: 200 }, function(new_Blob) { var img = document.createElement('img'); img.src = new_Blob.url; console.log("Convert successful"); console.log("Converted image URL"); console.log(new_Blob.url); filepicker.stat( new_Blob, { width: true, height: true }, function(metadata) { console.log("Converted image Dimensions:"); console.log(JSON.stringify(metadata)); } ); } );


the file to convert

A Blob pointing to the file you would like to convert.

a dictionary of key-value pairs that define the conversion
width: 200

Resize the source image to the specified width in pixels. Ignored if the file is not an image.

height: 200

Resize the source image to the specified height in pixels. Ignored if the file is not an image.

fit: 'clip'

Specifies how to resize the image. The default value is clip if fit is not declared. Possible values are:

clip Resizes the image to fit within the specified parameters without distorting, cropping, or changing the aspect ratio
crop Resizes the image to fit the specified parameters exactly by removing any parts of the image that don't fit within the boundaries
scale Resizes the image to fit the specified parameters exactly by scaling the image to the desired size
max Resizes the image to fit within the parameters, but as opposed to 'clip' will not scale the image if the image is smaller than the output size
align: 'faces'

Determines how the image is aligned when resizing and using the "fit" parameter. Defaults to cropping to the center of the image. Possible values are:

top Crop aligned with the top of the image
bottom Crop aligned with the bottom of the image
left Crop aligned with the left edge of the image
right Crop aligned with the right edge of the image
faces Search for faces, and if found, crop the image so that the faces are aligned in the center of the resized image.
crop: [20, 20, 100, 100]

Crops the image to the specified rectangle in pixels, given by [x, y, width, height], where x is the distance in pixels from the left edge of the image and y is the distance in pixels from the top edge of the image. For example, [0,0,100,100] would crop a 100x100 image starting from the top left corner of the image.

crop_first: true

Makes sure the image is cropped before any other conversion parameters are executed.The only value for this parameter is true.

format: 'jpg'

Specifies what format the image should be converted to, if any. Possible values are "jpg" and "png". For "jpg" conversions, you can additionally specify a quality parameter.

filter: 'blur'

Specifies which filter to apply to the image. Available filters are:

blur Blurs the image. You can additionally specify a "blurAmount" parameter. As you increase "blurAmount", the image becomes blurrier. Default value is 2.
sharpen Sharpens the image. You can additionally specify a "sharpenAmount" parameter. As you increase the "sharpenAmount", sharpening becomes more obvious. Default value is 2.
compress: true

For jpeg or png files, specifies whether image should be compressed. Possible values: true or false.

quality: 75

For jpeg conversion, specifies the quality of the resultant image. Quality should be an integer between 1 and 100. For more information about image quality and compression see the image compression page.

Integer or String
rotate: "exif" or rotate: 180

Rotate the image. Default is no rotation. rotate:"exif" will rotate the image automatically based on the exif data in the image. Other valid values are integers between 0 and 359, for degrees of rotation. Read more about EXIF rotation and associated issues.

watermark: '

Adds the specified absolute url as a watermark on the image.

watermark size
watermark_size: 30

Scale the watermark to the given size, which is a percentage of the base image (not the original watermark).

watermark position
watermark_position: 'top,right'

Align the watermark to the given edge(s) of the original image. Possible values for vertical position are "top","middle","bottom" and "left","center","right" for horizontal position. The two can be combined by separating vertical and horizontal with a comma. The default behavior is bottom,right

policy: POLICY, signature: SIGNATURE

If you have security enabled, you'll need to have a valid Filestack policy and signature in order to perform the requested call. This allows you to select who can and cannot perform certain actions on your site. Read more about security and how to generate policies and signatures

An optional dictionary of key-value pairs that govern how the converted file should be stored
location: 'S3'

Where to store the file. The default is S3. Other options are 'azure', 'dropbox', 'rackspace' and 'gcs'. You must have configured your storage in the developer portal to enable this feature. Note:> Rackspace, Azure, Dropbox and Google Cloud are only available on the PLUS and higher plans.

path: '/myfiles/1234.png'

The path to store the file at within the specified file store. For S3, this is the key where the file will be stored at. By default, Filestack stores the file at the root at a unique id, followed by an underscore, followed by the filename, for example "3AB239102DB_myphoto.png".

If the provided path ends in a '/', it will be treated as a folder, so if the provided path is "myfiles/" and the uploaded file is named "myphoto.png", the file will be stored at "myfiles/909DFAC9CB12_myphoto.png", for example.

If the multiple option is set to true, only paths that end in '/' are allowed.

Store Container
container: 'user-photos'

The bucket or container in the specified file store where the file should end up. This is especially useful if you have different containers for testing and production and you want to use them both on the same Filestack app. If this parameter is omitted, the file is stored in the default container specified in your developer portal.

Note: This parameter does not apply to the Dropbox file store.

Store Region
storeRegion: 'us-east-1'

The region where your storage container is located. This setting currently applies only to S3 buckets. If you are using a different bucket and region than the one you set up in your developer portal you can pass the storeRegion as part of your store options. If this parameter is not set we will do our best to determine the region your S3 bucket is located so that we can properly authenticate our connection request. You can find a list of the S3 regions here: in the "region" column.

Public Access
access: 'public'

Indicates that the file should be stored in a way that allows public access going directly to the underlying file store. For instance, if the file is stored on S3, this will allow the S3 url to be used directly. This has no impact on the ability of users to read from the Filestack file URL. Defaults to 'private'.

The function to call if a file is picked successfully.

We'll return a Blob as a JSON object with the following properties.

url The main Filestack file url on which all other operations are based.
filename The filename of the uploaded file.
mimetype The mimetype of the uploaded file.
size The size of the uploaded file in bytes, if available.
isWriteable Whether the file can be written to using filepicker.write.

Sample response

The function that is called on uploading progress events. The function will show the percent completed as a number out of 100. Multiple mode provides separate callbacks for all selected files.

We'll retrun a JSON object with the following properties:

progress Current progress as a float number.
filename The filename of the file being uploaded.
mimetype The mimetype of the file being uploaded.
size The size of the file being uploaded in bytes if available.

Sample response

The function to call if there is an error when picking a file.

Possible error codes on the FPError:

141 The inputted file cannot be found.
142 The user's file cannot be converted with the requested parameters.
143 General error when converting the file.
400 Bad parameters were passed to the server. This often will be the case when you turned on security but haven't passed up a policy or signature.
403 Invalid request - The policy and/or signature don't allow you to make this request. For more information see Security Documentation.

For more info about FPErrors, see Error Handling.

Sample response