New: the plugin is now translated into 64 locales, covering 39 languages — Albanian (Shqip), Arabic (العربية), Belarusian (Беларуская), Bosnian (Bosanski), Bulgarian (Български), Chinese (中文 — Simplified, Traditional and Hong Kong), Croatian (Hrvatski), Czech (Čeština), Danish (Dansk), Dutch (Nederlands — Netherlands and Belgium), Estonian (Eesti), Finnish (Suomi), French (Français — France, Canada and Belgium), German (Deutsch — informal, formal, Austrian and Swiss), Greek (Ελληνικά), Hebrew (עברית), Hungarian (Magyar), Icelandic (Íslenska), Indonesian (Bahasa Indonesia), Italian (Italiano), Japanese (日本語), Korean (한국어), Latvian (Latviešu), Lithuanian (Lietuvių), Macedonian (Македонски), Norwegian (Norsk — Bokmål and Nynorsk), Polish (Polski), Portuguese (Português — Portugal, Brazil and Angola), Romanian (Română), Russian (Русский), Serbian (Српски), Slovak (Slovenčina), Slovenian (Slovenščina), Spanish (Español — Spain, Mexico, Argentina, Chile, Colombia, Costa Rica, Dominican Republic, Ecuador, Guatemala, Honduras, Peru, Puerto Rico, Uruguay and Venezuela), Swedish (Svenska), Thai (ไทย), Turkish (Türkçe), Ukrainian (Українська) and Vietnamese (Tiếng Việt).
New: a “Savings on this site” panel on the Stats screen — a clear breakdown of how much your full-size images and their thumbnails were each reduced (from how much, to how much), calculated from your own data and kept separate from the shared account quota.
New: a sticky “Save Changes” bar on the settings screen with a live “unsaved changes” reminder, so edits — especially a freshly pasted API key and secret — are never lost by forgetting to save.
3.0.2
Security: tightened permission checks so users can only optimize, convert or reset media they are allowed to edit.
Fixed: files without thumbnails (PDFs, AVIF, small images) are now handled correctly — they optimize and show their savings, and no longer report a false error or keep reappearing in the Bulk Optimize list.
Fixed: optimization failures now report the real reason (e.g. a timeout or a missing file) instead of a generic “Unknown error.”
Fixed: free accounts that reach their test quota now see an upgrade prompt instead of an inaccurate paid-plan billing notice.
3.0.1
Performance and reliability improvements to the Kraken.io API connection, with broader server compatibility.
3.0.0
New: optimization support for WebP, AVIF, HEIC, HEIF and PDF (in addition to JPEG, PNG and GIF).
New: convert uploads to WebP, AVIF, JPEG, PNG or GIF on the fly, synced live between the Media panel and settings.
New: a Kraken.io control panel on the Media Library, Add Media and Plugins screens, plus a Dashboard widget — showing connection status, plan, quota usage, active settings and supported formats.
New: a dedicated Bulk Optimize with Kraken.io screen, reachable from the Media menu, the Media Library and the panel.
New: per-image savings and error badges in the Media grid and list, updated live as images optimize.
New: conflicting-optimizer detection with one-click deactivation of other image plugins.
New: “Who can optimize images” capability setting (all logged-in users by default).
New: a Support tab linking to the WordPress.org forum and a pre-filled email, with copyable diagnostics.
Security: API key and secret are now write-only and masked — never pre-filled or exposed in the page source; nonce and capability checks on all AJAX actions; uploads are content-verified; raw SVG upload disabled as an XSS precaution.
Change: the large 1536×1536 and 2048×2048 retina sizes are now off by default to save quota (filterable; existing choices are respected).
Change: legacy WebP companion options are deprecated in favour of Convert.
Fix: a now-resolved error no longer keeps showing an error badge after a successful re-optimization.
Fix: the bulk count now lists only supported image formats (no more HTML/other files).
Fix: division-by-zero when calculating savings on PHP 8; assets are cache-busted by file modification time.
2.7.0
Complete plugin rewrite with a modular OOP architecture.
Added WebP image generation and display support.
Added background processing for image optimization.
Added support for WP Retina 2x, NextGen Gallery and WP Offload Media.
Security: capability and nonce checks on the reset-all AJAX handler; input sanitization; whitelist validation for the settings tab parameter.
Requires PHP 5.6+ and WordPress 4.9+.
2.6.6
Security release to solve https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-38454
2.6.0
Added the ability to choose which image sizes get optimized.
Added the ability to change the chroma subsampling scheme for JPEG images.
Stability and compatibility improvements.
2.5.0
Optionally disable optimization of the main image for faster uploads.
Restrict the maximum dimensions of uploads (resizing), with sharpening enhancement.
Force a discrete JPEG quality value; preserve selected EXIF tags; auto-orient by EXIF.
2.0.0
Kraken.io settings moved to their own section (Settings → Kraken.io) with grouped Advanced Settings.
1.0.3
Added the “Krak ’em all” bulk optimization feature to the Media Library Bulk Actions menu.
1.0
First release: lossy and lossless optimization of JPG, PNG and GIF (including animated GIF), with automatic optimization of uploads and their thumbnails.
For the full version history of older releases, see the plugin’s WordPress.org changelog.
