Resize Image in Pixels, CM, MM & Inches Online (With DPI & KB Lock)
Change image width and height in Pixels (px), Centimeters (cm), Millimeters (mm), or Inches with 200/300 DPI calibration and optional Target KB File Size Lock for SSC, UPSC, IBPS, PAN Card, and HD printing.
Select or Drop Image Here
Drag & drop your image, paste from clipboard (Ctrl+V), or browse from device.
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Frequently Asked Questions
How do I resize an image in Centimeters (cm), Millimeters (mm), or Pixels (px)?
Upload your photo, choose your preferred measurement unit (Pixels, CM, MM, or Inches) at the top, select your target DPI (200 DPI for online exams or 300 DPI for printing/NSDL PAN), and enter your width and height. SizeSnap automatically converts physical dimensions into exact canvas pixels.
Can I set both custom dimensions (like 3.5×4.5 cm) and an exact KB file size (like 20KB or 50KB) together?
Yes! Check the "Lock Exact Target File Size in KB" box below the dimension inputs, pick 20 KB or 50 KB (or type any custom KB), and click Resize. SizeSnap will resize the dimensions, embed the JFIF DPI header, and lock the file size under your KB limit in one step.
How does changing DPI (200 DPI vs 300 DPI) affect CM and MM dimensions?
Physical units like 3.5 × 4.5 cm depend on resolution density (Dots Per Inch). At 200 DPI (standard for SSC/UPSC), 3.5 × 4.5 cm equals 276 × 354 pixels. At 300 DPI (standard for NSDL PAN Card and photo studio printing), 3.5 × 4.5 cm equals 413 × 531 pixels.
Will resizing stretch or distort my image?
Not when Aspect Ratio Lock is enabled. When you apply an exact exam preset (such as 140×60 px signature or 213×213 px PAN photo), Aspect Ratio Lock unlocks automatically so your output matches the strict portal pixel grid.
Are transparent PNG backgrounds preserved after resizing?
Yes. If you leave Target KB Lock unchecked and select PNG or WebP output, transparent alpha channels are strictly preserved throughout the canvas resize pipeline.