Image Resizer
Resize by pixel dimensions, percentage, or target file size. Target-size mode iteratively adjusts quality to hit your desired KB. Aspect-ratio lock on by default; common presets for Instagram, Full HD, etc.
Click here or drop an image
Result
Original
Resized
Three modes, one use case each
Pixel dimensions: when you need an exact width or height. Aspect-ratio lock (on by default) keeps the image from stretching — the other dimension is computed automatically. Presets cover the most common cases (Full HD, Instagram, OG image sizes).
Percentage: when you want “half the size” without doing math. 50% = each dimension halved (image is 1/4 the pixel count).
Target file size: when you have a hard file-size limit (email attachment, upload cap, avatar image). The tool iteratively adjusts JPG/WebP quality (binary search) to land within ±10% of your target. Only works for lossy formats; a target-size PNG would require quantization.
Upscaling caveats
Making an image larger than its original resolution doesn't add detail — it invents pixels via interpolation. Browsers use bilinear or bicubic interpolation for Canvas resizing, which is fine for modest upscales (1.5-2×) but visibly blurry beyond that. For serious upscaling use a neural network tool (Real-ESRGAN, waifu2x); those are not in-browser.
Quality drops with each re-save
Every time you re-save a JPG or WebP, you re-apply lossy compression. Resize once from your original; if you need multiple sizes, resize the original separately each time rather than resizing an already-resized copy.