Title: Pipe9 Media Optimizer
Author: Özgür Altunyurt
Published: June 21, 2026
Last modified: June 21, 2026
---
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# Pipe9 Media Optimizer
By [Özgür Altunyurt](https://profiles.wordpress.org/altunyurt/)
[Download](https://downloads.wordpress.org/plugin/pipe9-media-optimizer.1.5.2.zip)
* [Details](https://wordpress.org/plugins/pipe9-media-optimizer/#description)
* [Reviews](https://wordpress.org/plugins/pipe9-media-optimizer/#reviews)
* [Installation](https://wordpress.org/plugins/pipe9-media-optimizer/#installation)
* [Development](https://wordpress.org/plugins/pipe9-media-optimizer/#developers)
[Support](https://wordpress.org/support/plugin/pipe9-media-optimizer/)
## Description
Pipe9 Media Optimizer converts your uploaded images to WebP automatically — no batch
jobs, no manual steps, no complex configuration. When a browser supports WebP (all
modern browsers do), the optimized version is served instead of the original, reducing
page weight by 25-35% on average with zero visible quality loss.
**How it works:**
When you upload an image to WordPress, the plugin creates a WebP copy and stores
it alongside the original in `uploads/pipe9-media-optimizer/webp/`. When a visitor
loads a page, the plugin detects browser support via the `Accept` header and serves
the WebP version — either through server-level rewrite rules, HTML markup, or a
lightweight PHP endpoint.
**Key features:**
* **Automatic conversion** on upload — JPEG, PNG, and static GIF images are converted
to WebP as soon as they hit the media library. Animated GIFs are converted to
animated WebP via gif2webp or Imagick (previously a Pro feature — now free!)
* **Six serving strategies**: Apache rewrite rules (zero PHP cost — the fastest
option), HTML `` wrapping (single buffer scan per page), Nginx config
snippet (paste and go — includes theme image rules), PHP passthru endpoint (works
on any server), WP Engine optimized mode, or conversion-only mode (no serving
changes)
* **Theme image conversion** — scans and converts images inside active theme directories
* **Bulk conversion** — convert your entire existing media library with one click,
with a real-time progress bar
* **Media Library integration** — each image gets a format column showing WebP
status, with per-image convert and remove actions
* **Memory guard** — automatically detects when an image is too large to convert
without blowing through PHP’s memory limit, and skips it gracefully
* **Pluggable architecture** — modules register themselves via WordPress hooks;
the Pro add-on adds AVIF and animated format support through the same system
**Pro add-on** (separate purchase from pipe9.uk) adds:
* Static AVIF conversion(
JPEG/PNG/GIF AVIF) — even smaller files than WebP * Animated AVIF conversion (animated
GIF animated AVIF via ffmpeg)
## Screenshots
[⌊Plugin settings page with serving strategy selection⌉⌊Plugin settings page with
serving strategy selection⌉[
Plugin settings page with serving strategy selection
[⌊Media Library with format column and row actions⌉⌊Media Library with format column
and row actions⌉[
Media Library with format column and row actions
[⌊Bulk convert interface with progress bar⌉⌊Bulk convert interface with progress
bar⌉[
Bulk convert interface with progress bar
## Installation
1. Upload the `pipe9-media-optimizer` folder to `/wp-content/plugins/`
2. Activate the plugin through the Plugins screen
3. Go to Settings Pipe9 Media Optimizer
4. Choose your serving strategy (Auto-detect works for most setups)
## FAQ
### What image formats are converted?
JPEG, PNG, and static GIF images are automatically converted to WebP. Animated GIFs
are now also converted to animated WebP in the free version (via gif2webp binary
or Imagick). For animated AVIF conversion, use the Pro add-on.
### How much will this reduce my image sizes?
Typical savings are at least 25-35% compared to JPEG, and at least 15-25% compared
to PNG. Lossy WebP at quality 80 is visually indistinguishable from the original
JPEG but substantially smaller. Lossless WebP preserves PNG transparency with smaller
file sizes.
### Does this work with my hosting provider?
Yes. Apache rewrite mode generates static `.htaccess` rules with zero PHP overhead—
it’s the fastest option. Nginx and WP Engine modes show ready-to-paste config snippets.
A PHP passthru mode works on any server, including locked-down hosts that don’t
allow `.htaccess` overrides.
### Will this affect my existing images?
No. Only newly uploaded images are converted automatically. Use the Bulk Convert
tool on the settings page to convert your existing media library. You can also convert
existing images one by one in the media listing section.
### How do I verify it’s working?
Check the “Formats” column in Media Library list view — it shows which WebP copies
exist. Or use browser DevTools to inspect response headers (look for `Content-Type:
image/webp`).
### Does the Pro add-on require a separate installation?
Yes, the Pro add-on is a separate plugin that requires Pipe9 Media Optimizer (free)
to be installed and active.
## Reviews
There are no reviews for this plugin.
## Contributors & Developers
“Pipe9 Media Optimizer” is open source software. The following people have contributed
to this plugin.
Contributors
* [ Özgür Altunyurt ](https://profiles.wordpress.org/altunyurt/)
[Translate “Pipe9 Media Optimizer” into your language.](https://translate.wordpress.org/projects/wp-plugins/pipe9-media-optimizer)
### Interested in development?
[Browse the code](https://plugins.trac.wordpress.org/browser/pipe9-media-optimizer/),
check out the [SVN repository](https://plugins.svn.wordpress.org/pipe9-media-optimizer/),
or subscribe to the [development log](https://plugins.trac.wordpress.org/log/pipe9-media-optimizer/)
by [RSS](https://plugins.trac.wordpress.org/log/pipe9-media-optimizer/?limit=100&mode=stop_on_copy&format=rss).
## Changelog
#### 1.5.2
* Fixed double `.webp.webp` bug — `on_media_edited()` now checks MIME type via `
get_post_mime_type()` instead of file extension, preventing re-conversion of
images already converted to WebP by WordPress core
* Intermediate sizes loop now checks `$size['mime-type']` to skip WebP thumbnails
from WordPress core conversion
* Upload pipeline switched from hardcoded extension whitelist to MIME-based detection(`
image/*` except `image/webp`) — future-proof for any image source format
#### 1.5.1
* Refactored option prefix handling — removed dynamic `$prefix`/`$option_prefix`
variables from all `register_setting()` calls, replaced with hardcoded module
prefixes (e.g. `p9mo_webp`, `p9mo_avif`, `p9mo_animated_avif`)
* Removed `get_option_prefix()` method and `option_prefix` format key
* Removed `$prefix` parameter from `register_extra_settings()` in all modules
#### 1.5.0
* **Animated GIF WebP now in free version** — animated GIFs are converted to animated
WebP inline via gif2webp binary (preferred) or Imagick coalesceImages() fallback(
previously required the Pro add-on)
* Theme images now served via passthru/picture instead of themes .htaccess — simpler,
fewer rewrite rules, works on all server types
* Nginx config output now includes theme image location blocks with try_files fallback
* Extracted all inline JS to external files (media-actions.js, serving-settings.
js, bulk-convert.js) — ~700 lines of PHP-built JS eliminated
* Bulk convert UI consolidated into one parameterized JS component (replaces 4
near-duplicate per-module implementations)
* Resolved WordPress.org and PluginCheck review issues (translators comments, option
prefix uniqueness, ABSPATH guards, heredoc elimination)
#### 1.4.3
* cwebp binary support — Google’s command-line WebP encoder is now auto-detected
and preferred over Imagick/GD for artifact-free high-quality output
* Fixed WebP block artifacts (‘dots’, ‘crunchy’ look) at high quality settings —
Imagick now uses webp:method=6, webp:auto-filter, webp:preprocessing=2 for smooth
gradients
* Fixed bulk convert pagination hole — no longer stops when page 1’s posts all
have WebP files from previous single converts
* Fixed silent conversion failure when exec() is disabled — detect() now checks
P9MO_CAN_EXEC before selecting cwebp
#### 1.4.2
* Theme image conversion — automatically scans and converts images in active theme
directories
* Improved output buffer handling — skips AJAX, cron, and XML-RPC requests
* Bug fixes and stability improvements
#### 1.4.0
* Initial release of the refactored plugin with pluggable module architecture
* Pro add-on support with AVIF, Animated WebP, and Animated AVIF modules
## Meta
* Version **1.5.2**
* Last updated **20 hours ago**
* Active installations **Fewer than 10**
* WordPress version ** 6.4 or higher **
* Tested up to **7.0**
* PHP version ** 7.4 or higher **
* Tags
* [images](https://wordpress.org/plugins/tags/images/)[media](https://wordpress.org/plugins/tags/media/)
[optimization](https://wordpress.org/plugins/tags/optimization/)[webp](https://wordpress.org/plugins/tags/webp/)
* [Advanced View](https://wordpress.org/plugins/pipe9-media-optimizer/advanced/)
## Ratings
No reviews have been submitted yet.
[Your review](https://wordpress.org/support/plugin/pipe9-media-optimizer/reviews/#new-post)
[See all reviews](https://wordpress.org/support/plugin/pipe9-media-optimizer/reviews/)
## Contributors
* [ Özgür Altunyurt ](https://profiles.wordpress.org/altunyurt/)
## Support
Got something to say? Need help?
[View support forum](https://wordpress.org/support/plugin/pipe9-media-optimizer/)