WebP是Google开发的一种图像格式（就像png和jpg一样）。WebP格式（.webp）的图像通常要小得多，这可以使网站更快并且使用更少的带宽。
根据图像的不同，尺寸可能会缩小25％至70％。
当你上传不受支持的图片格式时，就会出现以下错误提示：
WordPress添加上传文件类型的的方法：
只需要添加以下代码到您的主题下的 functions.php 文件。
这里我们添加了对svg、ico、webp的支持；
add_filter('upload_mimes', 'tbi_upload_mimes');
function tbi_upload_mimes($mimes = array()) {
$mimes['svg'] = 'image/svg+xml';
$mimes['ico'] = 'image/x-icon';
$mimes['webp'] = 'image/webp';
return $mimes;
}我们（推荐）使用 Woody Snippets 插件管理您的php代码，避免更换、升级主题被官方文件替换。
没事最好别随便修改
如果你还想添加其它类型附件，可以参看下面 MIME 类型添加；
$mimes['jpg|jpeg|jpe'] = 'image/jpeg'
$mimes['gif'] = 'image/gif'
$mimes['png'] = 'image/png'
$mimes['bmp'] = 'image/bmp'
$mimes['tiff|tif'] = 'image/tiff'
$mimes['ico'] = 'image/x-icon'
$mimes['asf|asx'] = 'video/x-ms-asf'
$mimes['wmv'] = 'video/x-ms-wmv'
$mimes['wmx'] = 'video/x-ms-wmx'
$mimes['wm'] = 'video/x-ms-wm'
$mimes['avi'] = 'video/avi'
$mimes['divx'] = 'video/divx'
$mimes['flv'] = 'video/x-flv'
$mimes['mov|qt'] = 'video/quicktime'
$mimes['mpeg|mpg|mpe'] = 'video/mpeg'
$mimes['mp4|m4v'] = 'video/mp4'
$mimes['ogv'] = 'video/ogg'
$mimes['webm'] = 'video/webm'
$mimes['mkv'] = 'video/x-matroska'
$mimes['3gp|3gpp'] = 'video/3gpp'
$mimes['3g2|3gp2'] = 'video/3gpp2'
$mimes['txt|asc|c|cc|h|srt'] = 'text/plain'
$mimes['csv'] = 'text/csv'
$mimes['tsv'] = 'text/tab-separated-values'
$mimes['ics'] = 'text/calendar'
$mimes['rtx'] = 'text/richtext'
$mimes['css'] = 'text/css'
$mimes['htm|html'] = 'text/html'
$mimes['vtt'] = 'text/vtt'
$mimes['dfxp'] = 'application/ttaf+xml'
$mimes['mp3|m4a|m4b'] = 'audio/mpeg'
$mimes['aac'] = 'audio/aac'
$mimes['ra|ram'] = 'audio/x-realaudio'
$mimes['wav'] = 'audio/wav'
$mimes['ogg|oga'] = 'audio/ogg'
$mimes['flac'] = 'audio/flac'
$mimes['mid|midi'] = 'audio/midi'
$mimes['wma'] = 'audio/x-ms-wma'
$mimes['wax'] = 'audio/x-ms-wax'
$mimes['mka'] = 'audio/x-matroska'
$mimes['rtf'] = 'application/rtf'
$mimes['js'] = 'application/javascript'
$mimes['pdf'] = 'application/pdf'
$mimes['class'] = 'application/java'
$mimes['tar'] = 'application/x-tar'
$mimes['zip'] = 'application/zip'
$mimes['gz|gzip'] = 'application/x-gzip'
$mimes['rar'] = 'application/rar'
$mimes['7z'] = 'application/x-7z-compressed'
$mimes['psd'] = 'application/octet-stream'
$mimes['xcf'] = 'application/octet-stream'
$mimes['doc'] = 'application/msword'
$mimes['pot|pps|ppt'] = 'application/vnd.ms-powerpoint'
$mimes['wri'] = 'application/vnd.ms-write'
$mimes['xla|xls|xlt|xlw'] = 'application/vnd.ms-excel'
$mimes['mdb'] = 'application/vnd.ms-access'
$mimes['mpp'] = 'application/vnd.ms-project'
$mimes['docx'] = 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'
$mimes['docm'] = 'application/vnd.ms-word.document.macroEnabled.12'
$mimes['dotx'] = 'application/vnd.openxmlformats-officedocument.wordprocessingml.template'
$mimes['dotm'] = 'application/vnd.ms-word.template.macroEnabled.12'
$mimes['xlsx'] = 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
$mimes['xlsm'] = 'application/vnd.ms-excel.sheet.macroEnabled.12'
$mimes['xlsb'] = 'application/vnd.ms-excel.sheet.binary.macroEnabled.12'
$mimes['xltx'] = 'application/vnd.openxmlformats-officedocument.spreadsheetml.template'
$mimes['xltm'] = 'application/vnd.ms-excel.template.macroEnabled.12'
$mimes['xlam'] = 'application/vnd.ms-excel.addin.macroEnabled.12'
$mimes['pptx'] = 'application/vnd.openxmlformats-officedocument.presentationml.presentation'
$mimes['pptm'] = 'application/vnd.ms-powerpoint.presentation.macroEnabled.12'
$mimes['ppsx'] = 'application/vnd.openxmlformats-officedocument.presentationml.slideshow'
$mimes['ppsm'] = 'application/vnd.ms-powerpoint.slideshow.macroEnabled.12'
$mimes['potx'] = 'application/vnd.openxmlformats-officedocument.presentationml.template'
$mimes['potm'] = 'application/vnd.ms-powerpoint.template.macroEnabled.12'
$mimes['ppam'] = 'application/vnd.ms-powerpoint.addin.macroEnabled.12'
$mimes['sldx'] = 'application/vnd.openxmlformats-officedocument.presentationml.slide'
$mimes['sldm'] = 'application/vnd.ms-powerpoint.slide.macroEnabled.12'
$mimes['onetoc|onetoc2|onetmp|onepkg'] = 'application/onenote'
$mimes['oxps'] = 'application/oxps'
$mimes['xps'] = 'application/vnd.ms-xpsdocument'
$mimes['odt'] = 'application/vnd.oasis.opendocument.text'
$mimes['odp'] = 'application/vnd.oasis.opendocument.presentation'
$mimes['ods'] = 'application/vnd.oasis.opendocument.spreadsheet'
$mimes['odg'] = 'application/vnd.oasis.opendocument.graphics'
$mimes['odc'] = 'application/vnd.oasis.opendocument.chart'
$mimes['odb'] = 'application/vnd.oasis.opendocument.database'
$mimes['odf'] = 'application/vnd.oasis.opendocument.formula'
$mimes['wp|wpd'] = 'application/wordperfect'
$mimes['key'] = 'application/vnd.apple.keynote'
$mimes['numbers'] = 'application/vnd.apple.numbers'
$mimes['pages'] = 'application/vnd.apple.pages'