About the Image Resizer

The Image Resizer changes an image to exact pixel dimensions with an optional aspect-ratio lock. You can enter width and height manually or use the lock to keep proportions, and dimensions are capped at 8000px per side.

This tool runs entirely in your browser using the Canvas API. Your image never leaves your device.

How to use the Image Resizer

1. 1Open the Image Resizer and upload an image.
2. 2Enter width and height (toggle the lock to preserve ratio).
3. 3Click Download Resized.

How the Image Resizer works

For the Image Resizer specifically, it changes an image to exact pixel dimensions with an optional aspect-ratio lock. Image tools use the HTML Canvas API. An image is decoded into an in-memory bitmap, drawn onto a 2D canvas context, transformed pixel by pixel or via the context’s built-in filter pipeline, and re-encoded to your chosen format with canvas.toBlob(). Resizing changes pixel dimensions (capped at 8000px per side to protect browser memory); compression re-encodes at a lower quality to discard visual data and shrink the file; format conversion re-encodes the bitmap as PNG, JPEG, WebP, or BMP. JPEG has no alpha channel, so transparent regions flatten to white when you convert to JPEG — keep PNG or WebP when you need transparency. The Background Remover is a manual selection tool, not an AI model: you draw rectangles or freehand lassos over the areas to erase, and those pixels are cleared to transparency. Multiple selections stack, with undo and clear, and the quality of the result depends on how closely you trace the boundary. The Metadata Remover works by redrawing the image onto a fresh canvas, which discards the EXIF container (GPS, camera, timestamps) without altering the visible pixels. The HD Upscaler enlarges with bicubic interpolation plus an optional sharpening convolution kernel; it cannot invent detail that is not in the source, so very small images may stay soft. The Collage Maker fits images into a grid while preserving aspect ratio, and the Thumbnail Generator scales to platform-specific dimensions, cropping edges to cover the target aspect ratio.

How this tool handles your data. This tool runs entirely in your browser using the Canvas API. Your image is read into memory, processed on a canvas, and downloaded as a new file — it never leaves your device. The original file is never modified; a new image is generated for each operation.

Supported formats & limitations. The image tools support PNG, JPEG, WebP, and BMP. Dimensions are capped at 8000px per side to protect browser memory. JPEG output flattens transparency to white; keep PNG or WebP when you need transparency. The Background Remover is a manual selection tool, not an AI model — you draw the areas to erase.

Practical workflow. In practice, you work through a short sequence: 1. Open the Image Resizer and upload an image 2. Enter width and height (toggle the lock to preserve ratio) 3. Click Download Resized. It is well suited to fitting an image to an exact layout dimension; shrinking an oversized image for the web; creating a specific pixel size for a thumbnail.

Best practice. Resize to the exact dimensions your layout needs before compressing, and strip EXIF metadata from personal photos before sharing them publicly.

Tips & common pitfalls. With the Image Resizer in particular, fitting an image to an exact layout dimension. Resize to the exact dimensions your layout needs before compressing, since fewer pixels usually means a smaller file. Strip EXIF metadata from personal photos before sharing them publicly to remove GPS and camera data. For the Background Remover, zoom in and trace closely with the lasso for clean edges, and use Undo to step back. Keep PNG or WebP when you need transparency, because JPEG flattens transparent areas to white. Work with images under 25 MB for best performance.

Troubleshooting

The first thing to know about the Image Resizer: 8000px on either side to protect browser memory. If an image will not load, confirm it is PNG, JPEG, WebP, or BMP and under 25 MB. If dimensions are rejected, they exceed the 8000px-per-side cap — enter smaller values. If transparency turns white on export, you chose JPEG; switch to PNG or WebP to keep the alpha channel. If the Background Remover leaves halos, zoom in and trace the boundary more closely with the lasso and use Undo. If the HD Upscaler leaves the image soft, it cannot invent detail not in the source — start from a larger original. If the Collage Maker distorts images, it preserves aspect ratio by fitting within cells, so crop beforehand for an exact fill.

Common use cases

• Fitting an image to an exact layout dimension.
• Shrinking an oversized image for the web.
• Creating a specific pixel size for a thumbnail.

Frequently asked questions

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