How do I resize an image online for free?

Upload your image to KJSynthora Image Resizer, set your target width and height (or select a social media preset), and click Resize & Download. The resized image downloads instantly. No signup, no server upload — everything happens in your browser.

Can I resize multiple images at once?

Yes. KJSynthora supports batch resizing up to 20 images simultaneously. Upload multiple images, set the target dimensions, and download all as a ZIP file.

What image formats does this tool support?

Upload: JPG, JPEG, PNG, WebP, GIF, BMP, TIFF, AVIF, SVG. Download: JPG, PNG, WebP, AVIF. WebP and AVIF produce significantly smaller file sizes than JPG at the same quality.

Is it safe to resize sensitive images online?

Yes. KJSynthora Image Resizer is 100% browser-based. Your images never leave your device and are never uploaded to any server. All processing uses the HTML5 Canvas API locally in your browser.

What is the best image format for websites in 2025?

WebP is the recommended format for websites in 2025 — it provides 25-35% smaller files than JPG at equivalent quality and is supported by all modern browsers. AVIF offers even better compression (50% smaller than JPG) but has slightly less browser support.

🖼 IMAGE RESIZER · FREE · NO UPLOAD · 2025

Resize, Crop & Convert
Images Online Free

Batch resize, compress, convert to WebP/AVIF, add watermarks, apply filters — 100% browser-based. Your images never leave your device.

20

Batch Max

4

Formats

0%

Upload

∞

Free

📐 Resize & Convert

🖼️

Drop your image here

JPG, PNG, WebP, GIF, BMP, AVIF · Click to browse

Social Media Presets

Target Dimensions

Aspect ratio constraint

Width (px)

Height (px)

Resize Mode

Output Settings

Output Format

Quality: 85%

10%100%

Transform

🖼️

Upload an image to begin

💡 Format Tips

WebP25-35% smaller than JPG

AVIF50% smaller than JPG

PNGLossless — for logos/text

JPGUniversal compatibility

Quality 80-85%Best size/quality balance

✂ Crop Image

✂️

Drop image to crop

JPG, PNG, WebP supported

Crop Mode

Crop Coordinates (px)

Left (X)

Top (Y)

Width

Height

Output Format

📌 Enter crop coordinates or drag on the preview canvas to select crop area.

✂️

Upload image to crop

📦 Batch Resize

📦

Drop up to 20 images

Select multiple files or drag & drop

Batch Settings

Width (px)

Height (px, 0=auto)

Output Format

Quality: 85%

Filename Prefix

📦 ZIP file downloads automatically. Requires modern browser with ZIP support.

📦 Batch Queue (0 images)

No images added yet. Drop images in the left panel.

🎨 Filters & Enhancement

🎨

Drop image to enhance

Apply filters and adjustments

Quick Presets

Manual Adjustments

100

0

0°

0%

100%

Output Format

🎨

Upload image to apply filters

💧 Add Watermark

💧

Drop image to watermark

JPG, PNG, WebP supported

Watermark Text

Font Size (px)

Text Color

Opacity: 60%

Position

Watermark Style

Font Style

Output Format

💧

Upload image to add watermark

👁 Before / After Comparison

👁

Upload original image

Then process to see comparison

Comparison Settings

Resize Width for "After"

Compress Quality (%)

10%75%

Format

🖱 Drag the slider to compare before and after.

👁

Upload and process to see comparison

📋 EXIF Metadata Viewer

📋

Drop image to view EXIF

JPG files usually contain EXIF data

⚠ GPS coordinates in EXIF can reveal your location. Consider stripping EXIF before sharing images online.

📌 Stripping EXIF protects your privacy — removes camera model, GPS, date/time from the image file.

📋 EXIF Data

Upload an image to view its metadata.

Image Optimization Guides

Expert articles on image resizing, compression, WebP conversion, and web performance optimization.

All WebP Compression Resize SEO Guides

Image Resizer FAQ

Common questions about resizing, compressing, and converting images online

About KJSynthora Image Resizer

The most complete free browser-based image tool. Resize, crop, compress, convert, add watermarks, apply filters, and view EXIF — all without uploading a single byte to any server.

🔒

Zero Upload

All processing uses HTML5 Canvas API in your browser. Your images never leave your device — not even temporarily.

📐

Smart Resizing

Contain, cover, stretch, or pad modes. Lock aspect ratio. 9 social media presets. Pixel-perfect output.

📦

Batch Processing

Upload up to 20 images, resize them all at once, and download as a single ZIP file.

🌐

WebP & AVIF

Convert to next-gen formats. WebP is 25-35% smaller than JPG. AVIF is 50% smaller — perfect for website optimization.

🎨

Filters & Effects

8 filter presets plus manual control of brightness, contrast, saturation, blur, hue, sepia, invert, and opacity.

💧

Watermarking

Add text watermarks with custom position, font, size, color, opacity. Single, repeat, or diagonal placement.

👁

Before/After Slider

Interactive comparison slider shows original vs processed image side-by-side with file size savings.

📋

EXIF Viewer

View all image metadata including camera model, settings, GPS, and timestamp. Strip EXIF for privacy.

✂

Precise Crop

Crop with exact pixel coordinates. Free, 1:1, 16:9, 4:3, and 3:2 aspect ratio modes.

⚖ KJSynthora vs Other Image Resizers

Feature	KJSynthora	Squoosh	TinyPNG	Canva	Photoshop
Free	✓ Always	✓	⚠ 20/mo	⚠ Limited	✗ Paid
No server upload	✓ 100%	✓	✗	✗	✓
Batch resize	✓ 20 imgs	✗	✓	⚠ Paid	✓
WebP/AVIF output	✓	✓	⚠ Paid	✗	✓
Watermark	✓	✗	✗	✓	✓
Filters & Effects	✓	✗	✗	✓	✓
EXIF Viewer	✓	⚠	✗	✗	✓
Before/After Slider	✓	✓	✗	✗	✗
No signup	✓	✓	✓	✗	✗

Resize, Crop & ConvertImages Online Free

💡 Format Tips

📊 Comparison Results

Image Optimization Guides

Image Resizer FAQ

About KJSynthora Image Resizer

Zero Upload

Smart Resizing

Batch Processing

WebP & AVIF

Filters & Effects

Watermarking

Before/After Slider

EXIF Viewer

Precise Crop

⚖ KJSynthora vs Other Image Resizers

Resize, Crop & Convert
Images Online Free