Image Rotator

The Image Rotator rotates any image by 90, 180, 270 degrees, or any custom angle from -359° to +359°. Rotating is a constant need — phone photos taken in portrait often show up sideways, scanned documents come in rotated, screenshots sometimes have wrong orientation. This tool handles all common formats (JPG, PNG, WebP, GIF, BMP), preserves transparency, and lets you fix orientation in seconds without installing software.

Choose a preset rotation (90°, 180°, 270°) or enter a custom angle for fine-tuned rotation. For non-90°-multiple angles, the resulting image is larger than the original to accommodate the rotated content (corners now extend beyond original bounds). Fill color for the exposed corners is configurable (white, black, transparent, custom). All processing runs in your browser using the Canvas API so original images stay private. Output format can match input or convert during rotation (PNG to JPG, etc.).

Image rotation uses the Canvas API\u2019s 2D context transformation capabilities.

For 90° multiples (90, 180, 270):
1. Create a canvas with swapped dimensions (original height becomes width for 90/270)
2. Translate to center, rotate, draw image
3. Pixels map exactly — no loss or blur

For arbitrary angles (45°, 137°, etc.):
1. Compute the bounding box of the rotated image (corners extend beyond original)
2. Create canvas with that bounding box size
3. Translate to center, rotate, draw image
4. Empty corners are filled with the chosen background (white, black, transparent)
5. Pixels are interpolated during rotation, which introduces minor blur

Canvas matrix transform: ctx.translate(cx, cy), ctx.rotate(angle in radians), ctx.drawImage(-img.width/2, -img.height/2). The rotation origin is the canvas center by default.

Interpolation: the browser\u2019s default is bilinear for Canvas operations. Quality is decent for most rotations. For best quality on arbitrary angles, the image should be larger than the final display size so interpolation artifacts are hidden.

EXIF Orientation flag: JPEG photos often have an EXIF orientation tag (1-8) indicating how the image should be displayed. Some browsers auto-rotate based on this; others display as stored. Modern tools (this one) can read EXIF orientation and apply the correct rotation automatically.

Transparency: PNG, WebP, GIF support alpha channels. Rotation preserves transparency. Exposed corners on arbitrary-angle rotations default to transparent for these formats.

Background fill for JPEG: JPEG has no alpha. Rotating a JPEG to a non-90° angle requires a background color for the corners. White is the most common default; configurable.

Quality loss:
- 90/180/270 rotations: zero quality loss (pixel-exact mapping)
- Arbitrary angle rotations: minor interpolation blur
- Re-encoding to JPEG: additional lossy compression

Performance: rotation is O(pixels). Multi-megapixel images rotate in hundreds of milliseconds on modern devices.

Compared to image editors (Photoshop, GIMP), this tool is faster for simple rotations. Editors offer more features but are overkill for rotation alone.

Compared to operating system image viewers (Windows Photos, macOS Preview), this tool works in any browser without needing to install anything. OS tools are convenient if you already have them; this tool is always available.

Compared to phone photo apps, this tool doesn\u2019t compress your images further. Phone apps often re-encode and reduce quality; browser-based rotation preserves quality better.