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Resize Image Online

Change image dimensions to exact pixel values, scale by percentage, or constrain to a maximum width or height while preserving aspect ratio. Supports JPG, PNG and WEBP — output is full quality with no watermarks and no file-size limits.

Drop your image here

Supports JPG, PNG, WEBP — Max 20MB

Resize Complete!

Original Size
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New Size
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Resized

Features

  • Custom width & height
  • Maintain aspect ratio
  • JPG, PNG, WEBP output
  • No file size limit
  • 100% browser-based

Related Tools

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Free Online Image Resizer

Change the width and height of any image instantly, directly in your browser. Whether you're preparing thumbnails, social media posts or print assets, our resizer handles JPG, PNG and WEBP with pixel-perfect precision — completely free and private.

Features

Custom Dimensions

Enter any width and height in pixels for precise control over output size.

Aspect Ratio Lock

Enable the aspect ratio lock to prevent distortion when resizing.

Format Conversion

Resize and convert to JPG, PNG or WEBP simultaneously.

No Upload

All resizing happens client-side. Your images never leave your device.

Instant Preview

See the resized result immediately before downloading.

High-Quality Output

Uses canvas bicubic scaling for smooth, sharp results.

Who Uses This Tool?

UI DesignersCreate assets for multiple breakpoints without design tools.
BloggersResize featured images to exact dimensions required by CMS templates.
App DevelopersGenerate icon sizes for iOS and Android in seconds.
Print DesignersResize images to specific DPI requirements for print production.

Common Questions

Will resizing reduce image quality?
Downscaling generally preserves quality well. Upscaling beyond the original resolution will cause blurriness as pixels are interpolated.
What is the maximum output size?
Output is limited by your device's canvas memory. For most devices this is around 16,000 × 16,000 pixels.
Can I resize to a percentage instead of pixels?
Currently we support pixel dimensions. Enter your calculated pixel values based on the percentage you need.
Does aspect ratio lock work automatically?
Yes — enable the checkbox and changing either width or height will automatically calculate the other dimension.

Pro Tip

For social media, use these standard sizes: Instagram square 1080×1080, Facebook cover 820×312, Twitter header 1500×500, LinkedIn banner 1584×396. Bookmark this tool for quick access!

Did You Know?

72 DPI
Standard Screen Resolution
The web convention of 72 DPI dates to early Apple Macintosh screens in 1984. Modern displays are 96–500+ DPI. DPI only matters for print — web images are sized by pixels, not DPI. A 1920×1080 image is always 1920×1080 pixels regardless of its DPI setting.
4K = 3840×2160
Common Screen Resolutions
Common resolutions: HD = 1280×720, Full HD = 1920×1080, QHD = 2560×1440, 4K UHD = 3840×2160, 8K = 7680×4320. For web: never serve images larger than the largest screen they'll appear on — waste of bandwidth.
Bicubic
Best Scaling Algorithm
Bicubic interpolation (used in our resizer) samples 16 surrounding pixels to calculate each new pixel — producing the smoothest results for both upscaling and downscaling. It's slower than bilinear (4 pixels) or nearest-neighbor (1 pixel) but produces professional quality output.

Social Media Image Size Cheatsheet

PlatformTypeRecommended SizeFormat
InstagramSquare post1080 × 1080JPG/PNG
InstagramPortrait post1080 × 1350JPG/PNG
InstagramStory1080 × 1920JPG/PNG/MP4
FacebookFeed post1200 × 630JPG/PNG
Twitter/XIn-feed image1200 × 675JPG/PNG
LinkedInPost image1200 × 627JPG/PNG
YouTubeThumbnail1280 × 720JPG/PNG
PinterestStandard pin1000 × 1500JPG/PNG
WhatsAppProfile photo640 × 640JPG/PNG

You May Also Ask

What is the difference between resize and resample?
Resize changes the displayed size without changing pixel count (like adjusting DPI). Resample changes actual pixel count — adding or removing pixels. Our tool resamples images, changing the actual pixel dimensions. Resampling down (fewer pixels) always works well. Resampling up (adding pixels) creates new pixels by interpolation — quality degrades as you go above the original resolution.
What image size should I use for social media?
Facebook post: 1200×630. Instagram square: 1080×1080. Instagram portrait: 1080×1350. Twitter/X header: 1500×500. Twitter/X in-feed: 1200×675. LinkedIn post: 1200×627. YouTube thumbnail: 1280×720. Pinterest pin: 1000×1500 (2:3 ratio). These are 2024 recommended sizes — platforms may update them.
Can resizing fix a blurry or low-quality image?
No — enlarging a low-resolution image only makes the blur more visible. There is no pixel data to recover; the resizer creates interpolated estimates. AI-based upscalers (like Topaz Gigapixel, Real-ESRGAN) can produce better results for enlargement by using machine learning to infer detail, but they are specialized tools. Our resizer uses standard bicubic interpolation.

Common Mistakes

Upscaling small images expecting HD results
Enlarging a 200×200 image to 2000×2000 produces a blurry, pixelated result — the algorithm invents pixels but cannot recover real detail.
Source the highest-resolution original possible. Downscaling always works; upscaling has strict limits.
Resizing without maintaining aspect ratio
Stretching an image to non-proportional dimensions distorts people's faces and product shapes — always appearing unprofessional.
Use the "Maintain aspect ratio" lock. Calculate the correct proportional dimension before resizing.
Resizing after compression instead of before
Compressing to 60% quality then resizing amplifies the JPEG artefacts — you resize the blockiness too.
Always resize first, then compress as the final step in your workflow.