How to Rotate an Image by Angle

What the image rotator does

Use Image Rotator when you need to turn supplied image data by a chosen angle. It accepts an image in Base64 form, lets you choose whether the result expands to fit the rotation, and supports a fill color for areas created around the rotated image. The default angle is 90 degrees, expansion is enabled by default, and the default fill color is black.

This workflow is useful when an image needs a different orientation before you use it elsewhere. Because the input is image data rather than a file upload described here, prepare the image as Base64 text before entering it. A non-empty image value is required for processing.

How to rotate an image

1. Convert or obtain the image as Base64 text. Make sure the value represents image data and is not empty.

2. Enter the Base64 image data in the image input.

3. Enter the rotation angle as a number. Use 90 for a quarter-turn, or provide another angle for a different rotation. If you leave this field unchanged, the default is 90 degrees.

4. Choose whether to expand the resulting image. Expansion is enabled by default. When enabled, the resulting image can use a larger canvas for the rotated content; the exact dimensions depend on the source image and the requested angle.

5. Set a fill color if the rotation creates areas outside the source image. If you do not choose one, the default is black. For an RGBA image using black, the rotation fill is transparent under the tool's stated behavior; otherwise, the supplied fill color is used.

6. Start the operation and review whether it succeeds. The tool Base64-decodes the supplied value, opens it as image data, rotates it, and saves the result. Decoding, opening, rotation, or saving can produce an unsuccessful result if processing cannot be completed.

How to read the result

A successful result contains the rotated image in Base64 form, the requested angle, and the original and resulting dimensions. The output keeps the source image format when one is available; otherwise, it is saved as PNG. Use the returned dimensions to confirm how the selected angle and expansion affected the canvas rather than assuming a particular width or height.

An unsuccessful result means the operation could not be completed. Empty image data fails before useful processing can occur, and malformed or otherwise undecodable data may fail while the image is being opened. Processing can also fail if image handling or saving raises an exception. If that happens, check that the Base64 value represents a supported image and try again with a valid angle and fill color.

Worked example

You have a Base64-encoded image that needs a quarter-turn and want the rotated result to use the default expanded canvas.

Enter the non-empty Base64 value, set the angle to 90, leave expansion enabled, and start the operation.

A successful result has a Base64-encoded rotated image, the requested angle, and the original and resulting dimensions. The image format remains the source format when available; otherwise, the result is PNG.

Limitations

• The operation can fail during image processing, and the exact resulting dimensions depend on the source image, angle, and expansion choice. Black fill is transparent for an RGBA image under the stated condition, so it should not be treated as opaque in that case.

Common errors

• An empty or invalid Base64 value causes the operation to fail. Replace it with non-empty Base64 that decodes to image data, then run the rotation again.

FAQ

Can I rotate an image from Base64 text?

Yes, when the value is non-empty Base64 that can be opened as image data. Empty, malformed, or otherwise undecodable input can produce an unsuccessful result.

What angle does the image rotator use?

The default is 90 degrees. You can enter another numeric angle when you need a different rotation.

What format is the rotated image returned in?

The output keeps the source format when one is available. If no source format is available, the result is saved as PNG.