Free Image Resizer

What this image resizer does

This free online image resizer changes the pixel dimensions of any image while keeping quality high. Choose from 12 pre-set dimensions (Instagram post, YouTube thumbnail, US passport photo, etc.) or enter custom width and height. Lock the aspect ratio to prevent distortion, or pick a fit mode that handles mismatched aspects gracefully. Batch resize up to 20 images at once. Everything happens in your browser using the native Canvas API — no library required, no upload, no watermark. Perfect for prepping images for social media, printing passport photos, generating avatar variants, and getting exact dimensions for websites.

How to resize an image

1. Drop images onto the upload area (up to 20 at once).
2. Pick a preset from the dropdown, or leave “Custom dimensions” to type your own width and height.
3. Keep “Lock aspect ratio” on to prevent stretching (recommended for most cases).
4. Choose a fit mode if your target aspect doesn’t match the source:
   • Contain — image fits inside, with background color filling the rest
   • Cover — image fills the frame, may crop edges
   • Fill — image stretches to fill (may distort)
5. Optionally change format (keep original, or convert to JPG/PNG/WebP).
6. Click Resize. Each resized image appears with a download button.

Preset dimensions guide

Fit modes explained

Contain — safest option

The image is scaled to fit inside the target dimensions, with background color filling any leftover space. Nothing is cropped and nothing is distorted. Perfect when you can’t afford to lose any part of the image.

Cover — for edge-to-edge display

The image is scaled to fill the entire target frame. Edges may be cropped where aspects don’t match. Great for banner images and thumbnails where the whole frame must be filled.

Fill — exact dimensions, may distort

The image is stretched to exactly fit the target size. Aspect ratio is not preserved. Use only when the aspect already matches or when distortion is acceptable.

Features

• 12 preset dimensions for social media, documents, and avatars
• Custom width/height from 1 pixel to whatever your browser handles
• Lock aspect ratio to prevent unintentional stretching
• 3 fit modes — Contain, Cover, Fill — for handling aspect mismatches
• Batch resizing — up to 20 images at once
• Format conversion — JPG, PNG, WebP
• Quality control for JPG and WebP output
• Custom background color when using Contain mode
• No library needed — pure browser Canvas API, extremely fast
• 100% offline after first page load

Common use cases

Social media prep — Every platform has a “sweet spot” size for maximum display quality. Instagram compresses images above 1080 wide, so 1080 is the ideal upload size. LinkedIn banners look sharpest at 1584×396.

Passport and visa photos — Government submission systems require exact pixel dimensions. Our presets match the specifications for US and UK passports; adjust manually for other countries.

Website performance — Serving a 4000-pixel image to display at 800 pixels wastes bandwidth. Resize images to their actual display size before uploading.

WordPress featured images — Most themes crop featured images to a specific aspect. Prepping at the right ratio prevents surprising crops.

Email newsletters — Email clients don’t handle very large images gracefully. Resize to 600 pixels wide (email standard) before including.

PDF preparation — Before running images through our JPG to PDF converter, resize to reasonable dimensions to keep the PDF size manageable.

Print materials — For 300 DPI printing, calculate pixels: inches × 300. A 4×6 print needs 1200×1800 pixels.

Image resizer comparison

Pro tips

• Upscaling loses quality; downscaling doesn’t. Making a 500-pixel image bigger to 2000 pixels produces a blurry result. Making a 4000-pixel image smaller to 1000 pixels produces a sharp result.
• Combine with our Image Compressor for maximum file-size savings. Resize first, then compress the resized version.
• Save quality at 90 for JPG output — this looks visually identical to 100 but produces ~40% smaller files.
• For social media, “Cover” is usually the right fit mode — you want to fill the whole frame with your image, even if a tiny bit gets cropped at the edges.
• For document photos (passport, ID), “Contain” with a white background is safest — the whole face must be visible, no cropping allowed.
• Batch mode reuses your settings across every image. Great for creating consistent avatar sets or thumbnail batches.