How LessFlux Optimizes Images Externally
LessFlux does not optimize images directly on your WordPress server. Instead, it processes everything externally and returns optimized versions. This is one of the core differences compared to traditional optimization plugins.
Understanding how this works is important, because it explains why LessFlux does not slow down your site during processing and why results are not instant.
Why external optimization matters
Most optimization plugins run directly on your server. This means:
- higher CPU usage during processing
- slower admin experience during bulk operations
- possible timeouts on shared hosting
LessFlux avoids this completely by moving the heavy work outside your environment.
Your server only handles sending and receiving files, not processing them.
How the process works
When an image is uploaded or selected for optimization, LessFlux follows a structured flow:
- WordPress uploads the image and generates all standard sizes
- LessFlux detects the original file and all generated sizes
- Each file is sent to the LessFlux optimization system
- Compression is applied externally (lossy or lossless)
- Optimized versions are generated
- Files are returned to your site or made available through CDN delivery
This happens in the background and does not require you to stay on the page.
What gets optimized
LessFlux does not only optimize the original image. It processes all image sizes generated by WordPress.
- original uploaded image
- thumbnail
- medium
- large
- any custom sizes created by your theme or plugins
This is important because WordPress rarely serves the original image directly. Most of the time, it uses one of the generated sizes.
Compression behavior
LessFlux applies compression based on your settings:
- lossy compression for maximum size reduction
- lossless compression when quality must remain unchanged
Lossy compression usually provides the best results for web performance, as it significantly reduces file size while keeping visual quality acceptable.
Format handling
LessFlux can also handle modern formats depending on configuration:
- JPEG and PNG can be converted to WebP
- existing WebP or AVIF files can be recompressed
The goal is not just conversion, but overall size reduction.
What happens after optimization
Once images are processed, LessFlux handles them based on your settings:
- original files can be replaced with optimized versions
- or optimized files can be served separately
- CDN delivery can be used to serve files faster globally
In all cases, WordPress continues to function normally. Themes and plugins still request images the same way.
Why processing is not instant
Because optimization happens externally, there is a short delay between upload and completion.
- files are queued for processing
- optimization runs asynchronously
- results are applied once processing is complete
This delay is normal and ensures your server is not overloaded.
Common misconceptions
There are a few things users often misunderstand about external optimization:
- LessFlux does not slow down your site during processing
- it does not resize or crop images
- it does not control which image size WordPress serves
- it does not require you to keep the browser open
If you expect instant results or visible changes immediately after upload, it may seem like nothing is happening, but processing is simply running in the background.
Best practices
- keep automatic optimization enabled
- use lossy compression for most websites
- run bulk optimization once for existing media
- combine optimization with CDN delivery for best results
External optimization works best when it runs continuously in the background, without manual intervention.