Resize Image
Change image pixel dimensions while preserving or unlocking aspect ratio. Your files are never uploaded to our servers. ToolkitPoint processes them on your own computer, so confidential documents stay with you.
Processed in your browser. Your files are not uploaded.
How to use Resize Image
- Select a picture under "Select Image to Resize"; the width and height boxes fill with its original pixel size.
- Choose a "Method": Exact Pixels, Social Media & Standard Presets (now including passport, 4 x 6, 5 x 7 and A4 at 300 DPI), Percentage Scale, or Print size (mm, cm or inches at a DPI you set).
- In pixel mode, type a Width or Height and leave "Lock Aspect Ratio" ticked so the other box updates itself; untick it to set both freely.
- Set "Fit Behavior" (Cover, Contain or Stretch), the cover focus (centre, top, bottom, left, right), the resampling method (Lanczos-3 or fast) and, if you like, "Do not enlarge".
- Pick PNG, JPEG or WebP, set the quality slider and an optional largest size in KB, press "Resize Image Now", check the preview and download.
Worked example
Open a 4000 x 3000 photo, choose Print size, enter 10 x 15 cm at 300 DPI, keep Cover with the top focus, and export a PNG. The tool computes 1181 x 1772 pixels, resamples with Lanczos-3, and writes 300 DPI into the file so a print shop reads it as 10 x 15 cm.
When to use this tool
- Producing a 35 x 45 mm passport photo at 300 DPI (413 x 531 px) from a phone picture.
- Cutting a 4000-pixel camera photo down to a 1200 x 630 link-preview card under a size limit.
- Sending a photo to a print shop at exactly 4 x 6 inches with the DPI stored in the file.
Important limitations
Upscaling smaller images above their original pixel dimensions will enlarge existing pixels but cannot synthesize new fine optical detail.
Frequently asked questions
What is the difference between Cover, Contain and Stretch?
Cover scales the picture until it fills the frame and crops the overflow; the focus menu decides whether the centre, top, bottom, left or right part is kept. Contain fits the whole picture inside and leaves bars. Stretch forces the exact size and distorts the picture if the ratios differ.
Can I set the JPEG quality?
Yes. The quality slider (30 to 100 percent, default 92) applies to JPEG and WebP, and an optional largest size in KB lowers the quality until the file fits, or tells you if it cannot. PNG is lossless and has no quality setting.
How does print size mode work?
Enter a physical size and a DPI; the tool converts it to pixels (10 x 15 cm at 300 DPI is 1181 x 1772 px) and writes the DPI into PNG and JPEG files so print software reads the intended size. WebP has no standard DPI field, so use PNG or JPEG for print.
What is Lanczos-3 resampling?
It is a standard high-quality resizing filter computed in this page. It usually keeps edges and text sharper than the browser's default scaling, especially when shrinking a lot; a fast browser-scaling option is available for very large images.
Why are the bars white or transparent when I use Contain?
JPEG output fills the bars with the Contain background colour (white by default). PNG and WebP keep them transparent.
Does enlarging a small photo add detail?
No. Resampling only interpolates the existing pixels, so an enlarged photo looks smoother, not more detailed. Tick "Do not enlarge" to keep small photos at their size, or use the image upscaler for AI enlargement.