Resize image
Resize Image
Change photo size online: new width and height in pixels, or a preset
Resize Image changes picture width and height in pixels using your browser's canvas, with zero server uploads. Select ready-made presets for passport photos, social posts, and HD screens, or enter custom pixel dimensions. Export to JPG, PNG, or WebP with a 20 MB per-file upload limit.
- Runs in your browser
- Nothing uploaded
- No sign-up
- Free, no daily limits
- 1Add your file
- 2Choose settings
- 3Download
Drop your image here
Choose a fileClick to browse or drag and drop (JPG, PNG, WEBP) · up to 20 MB · nothing is uploaded
Popular uses
Social Media
Instagram, Facebook, Twitter
ID Photos
Passport, Visa, ID Cards
Wallpapers
Desktop, Phone, Tablet
App Icons
iOS, Android, Web
What is Image Resizing?
Image resizing changes the dimensions of your pictures to any size you need. Perfect for creating social media posts, preparing ID photos, or generating wallpapers for different devices.
Specific Size Resizers
Need to hit an exact KB limit or dimension for a form? Use our specialized tools:
100% Private: Your images are processed entirely in your browser. Nothing is uploaded to any server.
Last updated
Resize Image scales the pixel dimensions of photos, screenshots, and scans directly on your device. Every operation runs through your browser's HTML5 Canvas context, meaning your pictures never leave your computer or phone. Whether you need to fit strict application portal specifications or scale down graphics for web pages, the resizer changes dimensions without requiring accounts or subscriptions.
The tool accepts JPG, PNG, and WebP files up to 20 MB. It alters pixel dimensions, which usually decreases file weight as a secondary effect, but it does not let you target a specific kilobyte number directly. If an entrance exam or job portal mandates both pixel limits and a kilobyte ceiling, resize your photo here first, then open Compress Image to bring the file under your required kilobyte ceiling.
How it works
1. Drop or select your image
Drag your JPG, PNG, or WebP file into the upload zone or click to open your system file picker. Files up to 20 MB are loaded directly into browser memory.
2. Select a preset or enter custom dimensions
Pick from the Social Media, Print & ID, or Screen Sizes tabs, or click Custom Size to type your desired width and height values in pixels.
3. Verify the aspect-ratio lock
Keep the ratio lock enabled to adjust height automatically when you change width. Selecting a preset turns off the ratio lock to apply exact dimensions directly.
4. Choose output format and resize
Select JPG, PNG, or WebP under Output Format, confirm your target dimensions on the resize button, and click it to render the new image.
5. Download the resized image
Review the output preview and click Download Resized Image to save the file with its new dimensions added to the filename.
When you'd use it
Meeting entrance exam photo dimensions
Recruitment and exam portals like SSC, UPSC, and state PSCs require photos at exact pixel sizes such as 200 x 230 px or 413 x 531 px. Selecting the Passport Photo preset sets these dimensions without manual arithmetic.
Preparing social media assets
Platforms crop images that fail to match their preferred aspect ratios. Use the 1080 x 1080 px Instagram Post preset or 1280 x 720 px YouTube Thumbnail preset to ensure clean framing.
Scaling high-resolution camera photos for web use
Modern 48 MP smartphone cameras export pictures exceeding 6000 x 4000 px. Scaling the width down to 1920 px or 1200 px cuts down loading delays while preserving sharpness on modern displays.
Fitting display wallpapers
Scale travel photography to exact desktop resolutions like 1920 x 1080 px or phone screen sizes like 1170 x 2532 px so the operating system does not blur the image through runtime stretching.
How do pixel dimensions differ from file size in kilobytes?
Pixel dimensions measure the width and height of an image grid, while kilobytes measure the file's storage footprint on disk. Changing pixel dimensions alters the total number of pixels stored. For example, reducing a 2400 x 1600 px photo to 1200 x 800 px discards 75% of the total pixel count, which typically reduces file size significantly.
However, pixel scaling alone cannot hit an exact byte target like 50 KB because JPEG and WebP compression efficiency fluctuates based on scene complexity, textures, and color gradients. When preparing documents for official submissions, always set your required pixel dimensions here first, or combine your portrait with Photo & Signature Joiner if the portal requires a single combined file.
| Preset Name | Dimensions (px) | Aspect Ratio | Common Use |
|---|---|---|---|
| Passport Photo | 413 x 531 | 35:45 (7:9) | ID cards and exam applications (35 x 45 mm at 300 DPI) |
| ID Card Standard | 638 x 1004 | 54:85 | Badges and physical card prints (54 x 85 mm at 300 DPI) |
| Full HD 1080p | 1920 x 1080 | 16:9 | Standard monitor wallpapers and web banners |
| Instagram Post | 1080 x 1080 | 1:1 | Square feed posts and profile avatars |
| YouTube Thumbnail | 1280 x 720 | 16:9 | Video cover previews and presentation slides |
Source: TryDocsy Preset Specifications, checked October 29, 2026
Measured results: resizing a photographic image
In our measured session using a real 2048 x 1536 px smartphone photograph (sample-phone-photo.jpg, 2615.4 KB, captured on a Samsung phone at Prospect Park and released CC0), resizing to common presets yielded predictable reductions in storage footprint using Chrome's canvas rendering context at default 0.92 JPEG quality.
Resizing the 2615.4 KB original to the Passport Photo preset (413 x 531 px) produced a 92.4 KB file (94596 bytes), achieving a 96.5% file size reduction. Scaling to Full HD (1920 x 1080 px) produced a 759.5 KB file (777738 bytes), reducing storage footprint by 70.9%. All sample files and test parameters are preserved at reports/seo-batches/samples/b04/.
For exam portals with tight caps (such as 20 KB to 50 KB), note that resizing to passport dimensions alone leaves this detailed photograph at 92.4 KB. To reach limits under 50 KB, pair your resized file with Compress Image.
Why does choosing a preset unlock the aspect-ratio lock?
By default, the ratio lock stays enabled so altering one dimension automatically calculates the other from your source image's geometry. When you select a preset like Passport Photo (413 x 531 px) or Instagram Post (1080 x 1080 px), the tool deliberately turns off the aspect-ratio lock to apply the preset's exact numbers.
If your original image has different proportions, forcing both dimensions will stretch or compress the picture slightly. To avoid visual distortion, trim your image with Crop Image to match your target aspect ratio before resizing, or re-enable the lock after selecting the preset.
What happens to transparency when exporting to JPG?
The JPEG file container does not support alpha transparency channels. When you resize a transparent PNG or WebP and export it as JPG, the tool fills all transparent canvas areas with a solid white (#ffffff) background before encoding.
This prevents the dark or black artifacts that standard canvas exports produce when transparent pixels encounter lossy JPEG encoders. If you need transparent areas to stay see-through for logos or graphic overlays, select PNG or WebP as your export format.
For scanned paperwork or forms containing text, you can also extract the raw text using Image to Text (OCR) or scan embedded QR symbols with QR Code Scanner.
Frequently asked questions
Does resizing an image reduce its file size in KB?
Yes, reducing pixel dimensions almost always shrinks file size because the file contains fewer total pixels. However, it cannot hit an exact kilobyte target directly. To hit an exact limit like 50 KB or 100 KB, use Compress Image after resizing.
Will resizing a photo make it blurry?
Shrinking an image preserves sharpness because downscaling combines pixel information cleanly. Enlarging an image past its original dimensions forces the browser to interpolate pixels, which can make fine details look soft.
Why did my photo look stretched after picking a preset?
Presets set both width and height to match specific platform rules, which turns off the aspect-ratio lock. If your photo has different proportions, crop it first to match the preset's ratio so it fits without stretching.
Can I enter dimensions in inches or centimeters?
The tool works in pixels. Preset labels list physical dimensions like 35 x 45 mm at 300 DPI as helpful reference guides, but the browser canvas operates strictly on pixel values.
What is the maximum file size I can upload?
You can load image files up to 20 MB. The file is validated locally on your device as soon as you drop or browse it, before any canvas processing occurs.
Are my uploaded photos sent to an external server?
No. All resizing and encoding happen entirely in your web browser using HTML5 Canvas APIs. Your photos never leave your device.