01
Image Formats Best Image Format for the Web
Compare JPEG, PNG, WebP and AVIF for photos, transparency, quality, browser support and file size—and choose the right format for each job.
Open guide →Research · practice · performance
The Journal
Practical field notes for making web images smaller, faster, easier to discover, and safer to publish.
RISF / INDEX
01—07
Compression · Resizing · Formats · WordPress
Performance · SEO · Privacy
Performance · SEO · Privacy
Featured essay
Journal / 001
Image Compression
Image Compression: The Complete Guide
Learn how image compression works, when to resize or change format, and how to make images smaller without unnecessary quality loss.
·8 min read
Read the guide ↗
Start with the fundamentals
Seven definitive guides.
Each pillar owns one subject area, then connects to a deeper series of focused articles.
02
WordPress Images How to Optimize Images for WordPress
Optimize WordPress images before and after upload with the right dimensions, formats, compression, responsive delivery and performance settings.
Open guide →03
Image Compression Image Compression: The Complete Guide
Learn how image compression works, when to resize or change format, and how to make images smaller without unnecessary quality loss.
Open guide →04
Website Performance Image Optimization for Website Speed
Improve image-heavy pages by combining compression, correct dimensions, responsive delivery, lazy loading and priority hints.
Open guide →05
Image Resizing & Dimensions Image Resizing: The Complete Guide to Dimensions, Resolution and Aspect Ratio
Understand image resizing, pixel dimensions, aspect ratio, CSS pixels, device density and responsive source sizes so web images are sharp without being wastefully large.
Open guide →06
Image SEO Image SEO: The Complete Guide
Make images easier for search engines and users to understand with crawlable HTML, useful alt text, relevant context, descriptive filenames and fast delivery.
Open guide →07
Privacy & EXIF Photo Metadata & Privacy: What Images Can Reveal
Understand EXIF and other photo metadata, when location or device details may be present, and how browser-side re-encoding changes what is retained.
Open guide →Explore the library
Browse by subject.
Not a chronological blog. Each subject is a connected learning path with a clear parent guide.
018 articles
Image Compression
- How to Compress Images Without Losing Visible Quality
- Lossy vs Lossless Image Compression
- What Image Compression Quality Should You Use?
028 articles
Image Formats
Explore Image Formats →038 articles
Image Resizing & Dimensions
Image resizing, dimensions, aspect ratio, resolution, hero sizes, pixel density, and practical web image sizing.
- Does DPI Matter for Web Images? The 72 DPI Myth Explained
- Pixels vs Resolution vs File Size: What Actually Matters on the Web?
- Best Hero Image Size for Desktop and Mobile
048 articles
Image SEO
Explore Image SEO →058 articles
Privacy & EXIF
- Does Compressing an Image Remove EXIF Data?
- What Metadata Can Be Stored Inside a Photo?
- Do Online Image Compressors Upload Your Photos?
068 articles
Website Performance
- Image Optimization for Website Speed
- How Images Affect Core Web Vitals
- How to Optimize the Largest Contentful Paint Image
078 articles
WordPress Images
- How to Optimize Images for WordPress
- How to Compress Images Before Uploading to WordPress
- How to Use WebP Images in WordPress
Latest research
Recently published.
Focused answers, technical explainers, and practical workflows for people who publish images on the web.
Why Can a Compressed Image Be Larger Than the Original?
A compressed image can sometimes grow because of format choice, dimensions, source optimization or re-encoding. Here’s how to diagnose it.
·5 min read
How to Batch Compress Images Without Uploading Them
Compress multiple images at once without sending them to a server, then compare results and download the batch together.
·6 min read
Resize vs Compress Images: What Changes?
Learn the difference between reducing pixel dimensions and reducing encoded file size—and when using both gives the best result.
·6 min read
What Image Compression Quality Should You Use?
See what common quality settings change, where artifacts appear, and how to choose a practical quality level for web images.
·6 min read
Lossy vs Lossless Image Compression
Understand what lossy and lossless compression preserve, what they discard, and which approach fits photos, graphics and web images.
·6 min read
How to Compress Images Without Losing Visible Quality
Shrink image files while keeping them visually clean. Learn how resizing, format choice and quality settings work together.
·7 min read
WebP vs JPEG
See how WebP and JPEG differ in compression, quality, transparency, compatibility and when each format still makes sense.
·6 min read
WebP vs AVIF: Which Should You Use?
Compare WebP and AVIF for compression, visual quality, transparency, browser support and practical website workflows.
·6 min read
How Browser-Based Image Compression Works Without Uploading Files
See how a browser can decode, resize and re-encode an image locally using web platform APIs, and what that means for privacy, performance and limitations.
·6 min read
Do Online Image Compressors Upload Your Photos?
Some image tools send files to a server; others process them locally in the browser. Learn how to tell which model a tool uses before sharing sensitive images.
·6 min read