Description

Smart WebP Converter converts JPEG/PNG images and supported single-frame GIF images on new uploads.

By default the original stays intact. WebP sidecars are placed alongside the original and generated sizes. When WordPress renders attachment images or core/image blocks, a picture element supplies WebP and retains the original as browser fallback.

The optional Replace Original mode converts before an attachment is created, so WordPress builds its image metadata and thumbnails from the new WebP. This mode removes the old file and must be backed up/tested before enabling.

Other features:
* Quality control and optional metadata stripping.
* True lossless only with an ImageMagick installation supporting WebP.
* Native WordPress settings permissions/nonces.
* Conversion dashboard using locally rendered HTML/CSS (no remote scripts).
* Existing attachment alt text preserved; only meaningful editorial titles fill empty alt text.
* Existing database statistics and firexcore_webp_* settings retained from version 1.1.0.
* Visible WebP conversion status in Media Library and single-image sidecar regeneration for existing attachments.

Limitations and safeguards:
* New uploads are processed automatically. In Media Library, view WebP status and regenerate a missing sidecar for an existing image without replacing its original; no automatic bulk pass is run.
* A source PNG/JPEG remains PNG/JPEG in Media Library while Replace Original is OFF; a separate WebP file is generated where server support permits. The additional WebP file is reported separately.
* Site icons (including apple-touch-icon PNG), CSS backgrounds and raw URLs are not automatically rewritten.
* Animated GIFs are skipped to preserve animation. GIFs require Imagick even when single-frame.
* Large images above 40 million pixels are skipped.
* Raw HTML image URLs and CSS background images are not automatically rewritten.
* Attachment images hosted through a CDN using a different base URL may not receive a picture source. Originals remain functional.
* Legacy images from older releases (including webp-temp files) are not deleted or migrated automatically.
* Lossless requires Imagick; when unavailable, lossless requests are skipped rather than silently using lossy conversion.
* Requires PHP 7.4+ (version 1.1.0 required PHP 7.2+). Hosts on PHP 7.2/7.3 must upgrade PHP before installing this update.
* Enabling destructive replacement requires a separate deletion-confirmation checkbox at settings save time. Test replacement on staging with a backup first. It changes new upload filenames and MIME types and permanently removes the original for new uploads. Existing images removed by an earlier release can only be restored from an external backup.
* Smoke integration has passed on WordPress 6.7.10 and 7.1.4. WooCommerce, multisite and CDN variants still require testing.

Screenshots

Installation

Install the plugin as a directory named smart-webp-converter.
Activate it and open Smart WebP Converter > Settings.
Keep Replace Original disabled unless the site has been backed up and tested.
Upload a new JPEG or PNG. The Media Library retains its original type when Replace Original is off; use WebP Status to verify the additional .webp file.
For an existing image, open Media Library > attachment details > Manage conversion > Generate WebP sidecar now.

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Contributors & Developers

“Smart WebP Converter” is open source software. The following people have contributed to this plugin.

FireXCore

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Changelog

1.2.1

Add polished, responsive WordPress admin settings and dashboard with real statistics and attachment statuses.
Add an explicit, separate confirmation to enable destructive original replacement; disabling is always available.
Generate authentic release screenshots in disposable WordPress CI, and include branded banner/icon assets.
Retain PNG/JPEG filenames in Media Library when the non-destructive sidecar mode is active.

1.2.0

Convert before media registration when original replacement is enabled.
Generate durable sidecar WebP files for original and generated image sizes.
Deliver WebP via picture markup for attachment images and core/image blocks.
Preserve animated GIFs, existing alt text, and color profiles.
Avoid false lossless claims and duplicate conversion statistics.
Prevent repeated schema work and remove ineffective cron/cache-header logic.
Remove external Chart.js dependency and expensive full WooCommerce product enumeration.
Correct checkbox persistence, settings sanitization, and release documentation.
Preserve existing 1.1.0 option names and conversion statistics; new uploads require PHP 7.4+.
Remove historical remote Chart.js and smart suggestions UI; image conversion and basic statistics remain.
Show actual conversion status in Media Library and offer nonce-protected generation of sidecars for existing media without destructive replacement.