Image Resizer
Resize images in the browser with canvas—exact size, percentage, or preset. Output keeps the source MIME at about 0.95 quality. Not server-side; no HEIC/AVIF.
Drag and drop image here or click to select
Supported: PNG, JPG, JPEG, WEBP, GIF, BMP (not HEIC/AVIF)Practical tips
Set dimensions carefully
The maintain-aspect-ratio checkbox may not wire a full JS lock—enter width and height intentionally to avoid stretch.
Output keeps the source type
The resized file is re-encoded as the same MIME family at about 0.95 quality, not a free format switch.
Stay within limits
About 50 MB and a maximum of 10000×10000 pixels. Larger jobs may fail in the browser.
No HEIC or AVIF
Use JPEG, PNG, GIF, WEBP, or BMP. Convert phone HEIC elsewhere first if needed.
Exact, percentage, or preset
Choose custom pixels, social/web presets, or scale by percentage.
Client-side canvas
Resizing runs in the browser—images are not uploaded to a resize API.
Source MIME retained
Output stays in the same MIME type as the source, encoded at roughly 0.95 quality.
What this tool does
Image Resizer changes pixel dimensions of an image in your browser using canvas.
You can set exact size, scale by percentage, or pick a preset. It does not convert formats as its primary job.
How to use
Choose an image
Select JPEG, PNG, GIF, WEBP, or BMP within about 50 MB.
Pick a method
Use Custom Size, Preset Sizes, or Percentage.
Set targets carefully
Enter width/height or a preset. Do not rely on the aspect checkbox alone to prevent stretch.
Download
Run resize and download the re-encoded result.
Supported inputs and output
Input: JPEG, PNG, GIF, WEBP, BMP. Output: same MIME as the source at roughly 0.95 quality.
Maximum dimensions: 10000×10000. HEIC/AVIF are not accepted.
Processing and privacy
All resizing runs in your browser with canvas. Files are not uploaded to Toolomix for this operation.
Closing the page discards in-memory session data. See the Privacy Policy for general site practices.
Limitations
Known limits
- Aspect-ratio checkbox may not fully lock dimensions in JS (best-effort)
- Not server-side processing
- No HEIC/AVIF
- ~50 MB and 10000×10000 max
- Output MIME follows the source; quality ~0.95
Troubleshooting
If the image looks stretched, re-enter matching width and height manually rather than trusting the aspect checkbox alone.
If resize fails, reduce file size or dimensions and retry in a modern browser.
Frequently asked questions
Does Image Resizer upload my file?
No. Resizing uses the browser canvas. The image is not sent to Toolomix for resizing.
Which formats are supported?
JPEG, PNG, GIF, WEBP, and BMP. HEIC and AVIF are not supported.
Does Maintain aspect ratio always lock dimensions?
Not reliably. The checkbox may not fully wire to a JavaScript lock. Treat aspect handling as best-effort and enter width/height carefully.
What quality is the output?
The tool re-encodes at about 0.95 quality while keeping the source MIME type.
What are the size limits?
About 50 MB per file and a maximum dimension of 10000×10000 pixels.
Can I enlarge an image?
Yes, but upscaling cannot invent detail and may look soft. Stay within the max dimension limit.
Is this a server-side image service?
No. It is a client-side canvas tool, not a remote image-processing API.
Explore more free tools
Use Image Resizer
Resize locally. Set width and height carefully; aspect lock is best-effort.
