Email Image Compressor

Email Image Compressor

Convert and optimize images for different uses with this email image compressor. Transform images between formats while maintaining quality.

When to Use This Tool

Compressing images for email attachments and newsletters.

Key Benefits

• Avoid size limits
• Faster sending
• Quick downloads
• Mobile-friendly

Pro Tip

Keep total email under 1MB, individual images under 200KB for best deliverability.

Supported Formats

Format	Best For	Supports
JPEG	Photos	Lossy compression
PNG	Graphics, screenshots	Transparency, lossless
WebP	Web images	Both lossy and transparency
GIF	Animations	Limited colors

Optimization Tips

1. Use JPEG for photos to reduce file size 2. Choose PNG when you need transparency 3. Consider WebP for modern browsers 4. Compress images before uploading to websites

Images in Email

Email is the most constrained image environment left. Gmail clips messages above 102 KB of HTML, many corporate clients block remote images entirely by default, and mobile data still matters to a meaningful share of recipients.

Constraint	Target
Total email size	Under 100 KB where possible
Single image	Under 50 KB
Image width	600px (the standard email body width)
Format	JPG — WebP support in email clients is still patchy
Retina	1200px source displayed at 600px, quality 70

Two rules that matter more than compression:

• Always set alt text. With images blocked — the default in Outlook and for many Gmail

users — alt text is the entire message.

• Never put critical information only in an image. A promotional email whose offer exists

only as pixels is invisible to a third of its recipients and to every screen reader.

Sizing Before Compressing

Resizing beats compressing. Halving an image's dimensions removes 75% of its pixels, which no quality setting can match, and a 4000px photo displayed at 800px is wasting 96% of what it downloads.

Displayed at	Serve (1×)	Serve (2× for retina)
400px	400px	800px
800px	800px	1600px
1200px	1200px	2400px

Above 2× there is no visible benefit on any current display, and the file size keeps rising.

Quality Settings That Hold Up

Setting	Looks	Use for
95–100	Indistinguishable, large	Masters and print
80–90	Very good	Hero images, product photography
70–80	Good	Most web content
50–70	Visible artefacts on detail	Thumbnails
Below 50	Obvious	Nothing

Around 75–85 is where the curve bends: below it quality falls quickly, above it file size rises quickly for no visible gain.

Everything Runs Locally

Conversion and compression here use a canvas in your own tab. No file is uploaded, nothing is stored, and the work continues offline once the page has loaded. That is worth knowing for anything containing faces, documents or unreleased work — most online image tools upload by necessity, because they process server-side.

Getting the Rest of the Win

• Serve modern formats with a fallback. with AVIF, then WebP, then JPG.
• Always set width and height. Without them the page reflows on load, which

Google measures as Cumulative Layout Shift.

• Lazy-load below the fold — and never the hero, since loading="lazy" on it delays

the exact element Largest Contentful Paint measures.

• Strip metadata. EXIF can carry GPS coordinates and adds weight to every copy.