Image Compressor Tool (Free Online, Bulk, No Uploads)

Q: What quality should I use for photos?

Start around 80–85. If you see artifacts, increase quality. If the file is still too large, try resizing.

Q: Why didn’t PNG get much smaller?

PNG is lossless, so some images—especially photos—won’t shrink much. Try WebP or JPG for big savings.

Last updated: February 2026 ✅

Key Takeaways

💾

Compression is about size, not just “quality.” A small size drop can be “free,” but pushing quality too low can create visible artifacts. Start around 80–85 for photos.

🧰

WebP is the easiest “modern default.” For most websites, WebP gives strong size savings while keeping good visual quality and broad compatibility.

📷

JPG is still best for many photos. If you need maximum compatibility and the image is a photo with no transparency, JPG at 75–85 is a solid choice.

🔍

Resize first, then compress. Huge images scaled down by CSS waste bandwidth. Export near the real display size to get the biggest wins.

🧾

PNG is lossless and sometimes won’t shrink much. PNG is great for sharp UI screenshots and transparency, but large photo-like PNGs often compress better as WebP or JPG.

🚀

Bulk mode saves time. If you’re publishing a batch of images, compress up to 10 files and download them in one workflow.

Image Compressor Browser-safe, no uploads

Compress images locally in your browser. Choose JPG / WebP / PNG output, tune quality, and optionally resize. Bulk mode supports up to 10 files.

Input

Drag & drop images here (PNG, JPG, WebP).
Nothing is uploaded.

Status: Choose an image to begin.

Options Ready

Mode

Bulk mode (up to 10 files)

Single mode shows a preview. Bulk mode compresses a list one-by-one.

Output format

Tip: PNG is best for screenshots with sharp edges or transparency.

Quality (lossy)

Current: 82 (try 75–85 for photos)

PNG note

For big savings, choose WebP or JPG.

Background for JPG

JPG has no transparency. PNG/WebP keep alpha when possible.

Resize width (px)

Leave blank to keep original size.

Resize height (px)

Use one dimension + keep aspect ratio.

Keep aspect ratio

Helps avoid stretched images.

This tool compresses images using Canvas export. For best results, use WebP/JPG quality and optional resizing.

Preview (single mode) Input vs Output

Input —

Output —

Results 0 files

No files yet

Enable Bulk mode to compress up to 10 images at once.

Idle

⚙️ How To Use This Tool (Step-by-step)

Single image

Click Choose Image(s)
Keep Bulk mode off
Select:
- Output format (WebP recommended)
- Quality (start with 82)
- Resize (optional)
Click Compress
Click Download (last) (or Copy)

Bulk compression (up to 10)

Turn on Bulk mode
Choose up to 10 images
Pick output settings once
Click Compress (it becomes “Compress All” in practice)
Use Download All to download each file sequentially

💡 Mini Tutorial: Best Settings for Blog Images

If you want a reliable “default” workflow:

Set output to WebP
Set quality to 80–85
Resize feature images to a realistic width (often 1200px for banners)
Compress and download
Upload to WordPress

This usually produces a big size reduction while looking clean on modern screens.

“This tool compresses images directly in your browser without uploading files. Below you’ll learn what image compression is, how it works, common mistakes, and the best settings for web performance.”

Large images are one of the most common reasons websites feel slow. Even if your page is well-designed, heavy images can increase load times, use more mobile data, and reduce user retention.

This free Image Compressor helps you shrink image file sizes directly in your browser. It’s built for beginners and practical use: choose a format (WebP/JPG/PNG), adjust quality, optionally resize, and download the result. If you’re handling multiple images, Bulk mode compresses up to 10 files one-by-one for stability.

🖼️ What Is Image Compression?

Image compression is the process of reducing the number of bytes needed to store an image. The goal is simple: keep the image looking good while shrinking the file size.

There are two main approaches:

Lossless compression: preserves every pixel exactly. PNG is a common example. File size reduction depends heavily on image content.
Lossy compression: removes some information in ways that the human eye often doesn’t notice. JPG and WebP commonly use lossy compression.

For real-world web performance, most of your size savings come from choosing the right format and applying smart lossy settings (especially for photos).

📜 Short History of Image Compression

Image compression evolved with the web and digital photography.

JPG (JPEG) became popular for photos because it compresses complex images efficiently.
PNG became a standard lossless format for web graphics and screenshots, especially because it supports transparency.
WebP arrived later as a modern format designed to shrink files further while maintaining quality in many cases.

Today, most websites mix formats based on content type: photos, screenshots, icons, and transparent graphics all compress differently.

🧠 How Image Compression Works (Conceptual)

You don’t need to be a codec expert to use compression well. But it helps to understand what’s going on:

Lossy compression (JPG/WebP)

Lossy compression typically:

Analyzes visual patterns in the image
Simplifies details that are less noticeable
Stores an efficient representation rather than every raw pixel

Lowering quality means more simplification, which can cause artifacts such as:

blockiness
banding (visible gradients)
“mosquito noise” near edges
smearing of fine detail

Lossless compression (PNG)

Lossless compression looks for patterns like repeated colors and shapes. That’s why PNG is great for:

UI screenshots
flat graphics
text-heavy images
But PNG can be huge for photo-like images with lots of detail and noise.

📊 Why Use an Image Compressor?

If you publish online, compression helps with:

Faster page loads
Better mobile experience
Lower bounce rate
Improved Core Web Vitals
Reduced storage and bandwidth costs

Even one oversized hero image can slow an entire page. Compressing images is one of the highest-impact “quick wins” for performance.

📌 Common Use Cases

Compressing blog feature images before upload
Shrinking product images for faster browsing
Optimizing thumbnails for YouTube/blog embeds
Converting large PNG screenshots into smaller WebP versions
Preparing image batches for a gallery or portfolio page

🧩 Tool Workflow

Input → Decode → Optional Resize → Export (Format + Quality) → Download

Decode: your browser reads the image locally
Resize (optional): reduces pixel dimensions
Export: saves a new file in the format you selected
Download: you get the compressed result immediately

Workflow diagram showing input image processed into a compressed output — Basic workflow: input → processing → compressed output.

🔥 Quick Choices That Work

Goal	Best Output	Suggested Settings
Photo on blog posts	WebP or JPG	Quality 75–85
UI screenshots / code screenshots	PNG or WebP	PNG for perfect clarity, WebP for smaller size
Transparent images (logos / overlays)	WebP or PNG	WebP first, PNG fallback
Fastest “good enough” results	WebP	Quality 80, no resize unless needed
Big savings on huge images	WebP or JPG + resize	Resize near display size + quality 75–85

Comparison illustration showing a large image file versus a smaller compressed image file — Compression reduces file size while keeping acceptable quality.

⚠️ Common Mistakes (and how to avoid them)

Compressing PNG photos as PNG
PNG is lossless, so photos often stay large. Switch to WebP or JPG.
Using very low quality for photos
If you see artifacts, increase quality to 80–85.
Not resizing large images
A 4000px image displayed at 1200px wastes bandwidth. Resize.
Exporting JPG for transparent images
JPG removes transparency. Use WebP or PNG instead.
Compressing the same image repeatedly
Each lossy export can add artifacts. Keep an original copy.

✅ Checklist

✅ Click to open the pre-publish compression checklist

Chose the best format: WebP for most cases, JPG for photos, PNG for lossless needs.
Used quality 75–85 for photos (adjust if artifacts appear).
Resized images close to the real display size (avoid huge originals).
Checked transparency: WebP/PNG used where needed.
Verified file size feels reasonable (especially above the fold).
Kept an original copy before lossy compression.

✅ Click to open the performance checklist

Use lazy-loading for images below the fold.
Set explicit width and height to reduce layout shift.
Compress feature images before upload.
Prefer modern formats where possible (WebP).
Use fewer images per page when possible.

🧠 Mini Quiz

Test your understanding in 30 seconds.

📝 Quiz 1: Which format is usually best for photos?

Answer: WebP or JPG. They use lossy compression and usually shrink photos much more than PNG.

📝 Quiz 2: When should you choose PNG?

Answer: When you need lossless output, sharp edges, or transparency—especially for UI screenshots and graphics.

📝 Quiz 3: What’s the biggest “hidden win” besides quality?

Answer: Resizing. Exporting closer to the display size often reduces file size more than changing quality.

📝 Quiz 4: Why avoid re-compressing the same JPG repeatedly?

Answer: Each lossy export can add artifacts. Keep an original and compress once from the source.

❓ FAQ

Quick answers to common questions about image compression.

❓ Does this tool upload my images?

No. Your files are processed locally in your browser.

❓ What quality should I use for photos?

Start around 80–85. If you see artifacts, increase quality. If the file is still too large, try resizing.

❓ Why didn’t PNG get much smaller?

PNG is lossless. Some images (especially photos) don’t compress well as PNG. Try WebP or JPG for big savings.

❓ Is WebP safe to use on websites?

Yes. WebP is widely supported on modern browsers and is a strong default for web performance.

❓ What’s better: lowering quality or resizing?

Resizing often delivers the biggest size reduction with fewer visible artifacts. Do resize first, then fine-tune quality.

🔗 Recommended Reading

Image Compressor Tool (Free Online, Bulk, No Uploads)

Key Takeaways

Image Compressor Browser-safe, no uploads