Online Batch Image Resize Tool
Batch process multiple images: adjust image width and height by pixels. Processing takes place locally in your browser.
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Online Batch Image Resize Tool
Batch image resize accepts up to 30 selected images and applies one shared resize configuration to every image. The default mode uses pixels, targets 800 by 600, selects width and height, and keeps the source aspect ratio.
The unit can be pixels or percentage. In percentage mode the width and height values are percentages of each source image; in pixel mode they are output pixel dimensions. Switching to percentage resets both fields to 100, while switching back to pixels uses the first loaded image's dimensions or the 800 by 600 fallback.
Width and height with Preserve original aspect ratio enabled uses the requested width and calculates height from each image's own ratio. Disabling the checkbox allows independent width and height values. Width only or height only always calculates the other dimension from the source aspect ratio.
Verified examples for a 1600 by 900 source: 800-pixel width with ratio preserved produces 800 by 450; independent 50% width and 25% height produces 800 by 225; a 450-pixel height-only resize produces 800 by 450. Calculated dimensions are rounded to whole pixels.
Each output dimension is constrained to 1 through 10,000 pixels, each output is rejected above 24,000,000 pixels, and the complete batch is rejected above 40,000,000 output pixels. These checks reject output dimensions above the stated limits before allocating output canvases. They do not guarantee that every device has enough memory for a large valid batch.
Every input must have an image MIME type, be at most 25 MiB and decode to no more than 24,000,000 pixels. The selected batch is capped at 100 MiB and 40,000,000 decoded source pixels; selecting more than 30 files rejects the batch.
The browser redraws each source on a canvas using its native image resampling and exports PNG, regardless of the input format. Output names use the source base name plus -resize.png. Download all starts separate downloads about 180 ms apart; it does not create a ZIP, preserve animation or provide JPEG/WebP quality controls. Processing stays in the browser and does not upload images.
In Width and height mode with aspect ratio enabled, width takes precedence and the height field is ignored. For independent 50% × 25% output, turn that checkbox off. Width only and Height only are explicit radio modes; leaving a field blank does not select them. Empty, nonfinite, zero or negative values become 1 before calculation. Rounded dimensions are at least 1 pixel. When preserving aspect ratio, including width-only and height-only modes, a calculated side above 10,000 pixels rejects the operation. Only independent width-and-height mode clamps each side to 1–10,000 pixels. Integer pixels may approximate the original ratio. Finally, outputs above 24MP each or 40MP per batch are rejected.
Per image: ≤25 MiB and ≤24,000,000 pixels. Per batch: ≤100 MiB and ≤40,000,000 pixels. Selecting over 30 files or any invalid image rejects the whole batch.
Processing takes place locally in your browser.