Compress Image

Why Compress Images?

Large images slow down websites, eat up storage, and make sharing difficult. Image compression reduces file size while maintaining visual quality, making your photos faster to load, easier to email, and cheaper to store.

According to Google (2024), as page load time increases from 1 to 10 seconds, bounce probability increases by 123%. Deloitte and Google found that every second delay in mobile load speed causes an average 12% decrease in conversion rates. The HTTP Archive reports that images account for nearly a third of a typical web page's total weight.

Common scenarios where you need to compress images:

• Website optimization: Google recommends images under 200KB for fast page loads. Compressed images improve Core Web Vitals scores and SEO rankings.
• Email attachments: Most email providers limit attachments to 25MB. Compressing photos lets you share more images in a single email.
• Social media: Platforms like Instagram and Twitter re-compress uploads. Pre-compressing gives you control over the final quality.
• Cloud storage: Compressed images use less Google Drive, Dropbox, or iCloud space, saving you money on storage upgrades.
• App development: Smaller image assets mean faster app downloads and better user experience on mobile networks.

How PDFJolt Compresses Images Differently

Most online image compressors (TinyPNG, Compressor.io, Squoosh) upload your photos to remote servers for processing. Your vacation photos, ID scans, and private screenshots travel across the internet to someone else's computer.

PDFJolt compresses images entirely in your browser using the HTML Canvas API. When you drop an image into PDFJolt, it never leaves your device. The compression engine runs locally, producing your optimized image without any network transfer. This means:

• Complete privacy — your personal photos stay on your device
• Faster processing — no upload/download wait time
• Works offline once the page is loaded
• No file size limits imposed by upload bandwidth

Understanding Image Formats

JPEG (Joint Photographic Experts Group)

Best for photographs and complex images with gradients. JPEG uses lossy compression — it discards some color data to achieve smaller files. At 80% quality, the difference is typically invisible to the human eye.

WebP

A modern format developed by Google that produces files 25-35% smaller than JPEG at equivalent quality. Supported by all modern browsers (Chrome, Firefox, Safari, Edge). The best choice for web optimization.

PNG (Portable Network Graphics)

A lossless format that preserves every pixel perfectly. Best for screenshots, logos, and images with text or sharp edges. Files are larger than JPEG/WebP but quality is never degraded.

PDFJolt vs. Other Image Compressors

Feature	PDFJolt	TinyPNG	Squoosh	Compressor.io
Price	Free (5/day)	Free (20/mo)	Free	Free (limited)
Privacy	Client-side	Cloud upload	Client-side	Cloud upload
Quality control	Adjustable slider	Auto only	Adjustable	Adjustable
Batch processing	Coming soon	20 at once	No	No
Output formats	JPEG, WebP, PNG	PNG, JPEG	Many	JPEG, PNG
Account required	No	For API	No	No
Works offline	Yes	No	Yes	No

Tips for Best Compression Results

1. Start at 80% quality. This is the sweet spot where files shrink significantly without visible quality loss.
2. Use WebP for web. If your images are for a website, WebP gives the best file size with excellent quality.
3. Keep originals. Always save a copy of your original image before compressing, in case you need the full-quality version later.
4. Consider dimensions first. If your 4000×3000 photo will display at 800×600, resize it first with our Image Resizer, then compress. You'll get much smaller files.