Image Resizer – Resize Photos and Images Online

Image Resizing & Dimensions Guide

Image Resizer — Free Online Dimension & File Size Reducer

Resize JPG, PNG, WebP, and HEIC images to exact pixel dimensions, percentage scales, or specific file size limits (like 20 KB, 50 KB, or 100 KB for government forms and job portals). Fast, free, and processed entirely inside your browser.

Exact Pixels & Percentage Scaling

Change dimensions with mathematical precision. Lock aspect ratio to prevent stretching, or enter custom width and height in pixels (px), millimeters (mm), or centimeters (cm) for official photo requirements.

Target File Size Compression (KB & MB)

Need an image under 50 KB or 100 KB for SSC, UPSC, IBPS, or passport portals? Select our Target Size feature to automatically calibrate JPEG compression and resolution to hit your required file size limit.

Social Media & Web Presets

One-click presets calibrated for Instagram posts (1080×1080), Instagram Stories (1080×1920), YouTube thumbnails (1280×720), Facebook covers, LinkedIn banners, and WhatsApp display pictures.

100% Client-Side Privacy

Your personal photographs are never sent over the Internet to remote servers. All resampling calculations execute directly on your device using HTML5 Canvas APIs, ensuring absolute privacy.

Standard Image Dimension Requirements

Platform / Use Case Recommended Dimensions Aspect Ratio Optimal File Format
Instagram Square Post 1080 × 1080 px 1:1 JPG or WebP
Instagram Portrait Post 1080 × 1350 px 4:5 JPG (Max sharpness)
Instagram / TikTok Story 1080 × 1920 px 9:16 JPG / PNG
YouTube Video Thumbnail 1280 × 720 px (Min 640px width) 16:9 JPG or PNG (< 2 MB)
Government Exam Signatures (UPSC/SSC) 140 × 60 px (10 KB to 20 KB) ~7:3 JPG (Grayscale or color)
Standard Passport Photo Print 413 × 531 px (35 × 45 mm at 300 DPI) 7:9 Glossy JPG at 300 DPI

How to Resize an Image Online

1

Upload Photo

Drag your JPG, PNG, or WebP photo into the studio or click Choose Image.

2

Choose Mode

Select By Pixels for exact measurements, By Percentage for scaling, or choose a social preset.

3

Lock Aspect Ratio

Keep Maintain Aspect Ratio enabled to ensure your photo scales proportionally without distortion.

4

Resize & Download

Select output format and quality, then click Resize Image to download instantly.

Frequently Asked Questions

Helpful answers on photo resizing, aspect ratios, and compression formats.

How do I resize an image without losing quality?

To preserve image clarity, always resize downward (downscaling) rather than significantly enlarging a tiny image. Ensure Maintain Aspect Ratio is turned on to avoid stretching. Using high-quality resampling (bicubic interpolation) and saving in WebP or high-quality JPG preserves sharp details.

Can I resize an image to a specific KB limit (e.g. 50KB or 100KB)?

Yes! Check the "Target File Size" option in the right-hand panel, choose a target size like 50 KB or 100 KB, or enter a custom amount. The tool will automatically adjust resolution and compression quality to hit your requested size constraint.

What is the difference between image resizing and cropping?

Resizing changes the total pixel resolution of the complete photograph without removing any subject content. Cropping trims away outer edges or alters the framing, discarding unwanted areas. Use our Image Cropper if you need to trim boundaries.

Does PixDok support PNG images with transparent backgrounds?

Yes. When resizing PNG images, alpha channel transparency is preserved. If you export as PNG, transparent elements remain transparent.

Are my files uploaded to your servers?

No. PixDok Image Resizer is 100% browser-based. All image processing executes locally in your device's memory using JavaScript and HTML5 canvas. Your images are never transmitted or stored on external servers.

Independent Online Image Tool

PixDok Image Resizer is a free, independent digital productivity utility. Output image file size estimation is calculated based on standard entropy formulas; actual compressed size may vary slightly based on photographic noise and color complexity.

Digital portrait and raster image preparation conforms to ISO/IEC 19794 biometric formatting requirements, ensuring neutral lighting, true-color rendition, and high-density rasterization for identity applications.
— ISO/IEC 19794 Biometric Data Interchange & PixDok Image Standards