Can this be done? Create 50×50 thumbnails of all existing featured images?

There are lots of plugins that do this one way or another including:

I wouldn’t recommend reinventing the wheel. If you’re particularly worried about it, you might looking into TGM Plugin Activation to suggest to people in the Dashboard that they install and use the plugin.

Related Posts:

  1. How do I regenerate thumbnails?
  2. Add Title Attribute to WordPress Image the_post_thumbnail
  3. Display Category Thumbnail and links in Woo commerce
  4. Replacing Gutenberg Featured Image control?
  5. oEmbed, thumbnails and wordpress
  6. the_post_thumbnail scaling not hard cropping
  7. Add Image Dimensions to Media Library Tab on Media Upoader
  8. Featured Image Inherited from Parent Page
  9. Change wording of default thumbnail metabox
  10. Specific featured image for each category
  11. how to pull images with no add_theme_support(‘post_thumbnails’)
  12. Can WordPress crop only the post thumbnails?
  13. Query the post which have a thumbnail
  14. Adding schema itemprop image to the_post_thumbnail with filters
  15. How to show a featured image as current?
  16. How can I get a different image size, if all I have is the link?
  17. Show current page featured image in sidebar
  18. How do I get a random image from subset of images in media gallery?
  19. Importing featured image to posts, duplicates the image
  20. PDF Image in content
  21. How do I set a featured image (thumbnail) by image URL when using wp_insert_post()?
  22. Why does the Hard Crop option Scale?
  23. Use post thumbnail as div background
  24. How do I set the default “feature image” size?
  25. Featured Image missing in WordPress 3.2 Admin
  26. Change post thumbnail using front end post edit form
  27. Featured image thumbnail sometimes in content, sometimes changes header images
  28. How to add multiple featured images to post/page without a plugin
  29. Function to replace the url of featured images in the wordpress database?
  30. has_post_thumbnail gives always TRUE
  31. Displaying wordpress image size as array used for page builder
  32. Setting a default placeholder image WITHOUT link
  33. If I Regenerate Thumbnails, would WordPress delete the existing Thumbnails and replace them with ‘new copies’?
  34. how to use first post image as thumbnail on wordpress
  35. Make the first image the post thumbnail without setting it as the featured image
  36. MultiPostThumbnails for Custom Post Type
  37. set a chosen image-file-input as a featured image from wp frontend
  38. Aligning the thumbnail image
  39. WordPress Featured Image function recreate
  40. How do get post thumbnail into plugin?
  41. Using Featured Image as Hero Background
  42. Default Featured Image from Post content
  43. upload or auto setup feature photo by user avatar
  44. How to replace featured image upload option with the post media image option
  45. How to create resized versions of images added with wp_insert_attachment
  46. Can I insert the feature image inside the content, after any paragraph?
  47. Set Post Thumbnails in Percents
  48. WordPress returns old thumbnail size after changing media settings
  49. get_the_post_thumbnail() returns nothing?
  50. Display a thumbnail outside of the loop for a page
  51. How to use get_the_title with text on the ‘alt’ of the_thumbnail array?
  52. remove_image_size doesn’t seem to be working
  53. Get Featured Image Outside Loop Not Working
  54. Responsive scaling of image for the_post_thumbnail() [closed]
  55. images not showing despite using add_theme_support(‘post-thumbnails’);
  56. post thumbnail: increase dimension if smaller than… Possible?
  57. Displaying caption with featured image
  58. add_theme_support post-thumbnails not working
  59. Trying to show WordPress category query result as background image
  60. How risize a thumbnail?
  61. custom thumbnail image size not working
  62. Comparison Operators not working for conditional author post thumbnails
  63. Assign SQL ‘post_thumbnail’ column as featured image
  64. Default thumb – how to set it
  65. How to get featured image thumbnail to open larger version in attachment page?
  66. How To Use YouTube Url Stored In Custom Field To Get Video Image and Set it As Featured Image
  67. Display post thumbnail in foreach loop
  68. How to update custom image sizes?
  69. My Gallery Photos are showing in the post’s excerpts
  70. featured images twenty eleven theme
  71. Picture inserted in the post not showing in “Gallery”
  72. How to add featured images to posts from a category
  73. featured image is not showing
  74. Change featured image when changing viewport
  75. How to change the format of thumbnails into wordpress theme?
  76. How to calculate the sum of all featured thumbnail height on WordPress?
  77. How to create thumbnails programmatically?
  78. Thumbnails regenerate wp_generate_attachment_metadata
  79. Missing image size
  80. Usage of add_image_size (for featured image)
  81. Featured image: Dynamic image sizes when enlarged with javascript
  82. Smaller Size for featured images
  83. Featured image doesn’t appear in Blog index
  84. Remove Featured Image based on Date
  85. set_post_thumbnail() shows Unattached on backend under Media
  86. How to show only 2nd featured img on home/blog
  87. Echo recent posts each with its own respective featured image
  88. How to get post thumbnail to be equal to set media size
  89. Add notice to add image popup
  90. Mass/Bulk assign featured images to posts
  91. setting featured image is not working while running script in background, works when running that script from browser
  92. WordPress save thumbnail but don’t show it [closed]
  93. How to modify responsive images in post thumbnails
  94. get_the_post_thumbnail() – Invalid argument supplied for foreach() in /wp-includes/post-thumbnail-template.php on line 64
  95. Different thumbnail size than actual picture in post
  96. How to get the featured image inside of a single-.php template?
  97. Where is the template from the_post_thumbnail()?
  98. Get Post Thumbnail Outside of Loop
  99. Theme:Twenty Fourteen, How to remove featured image on single post page for particular category
  100. Hot to change resized image link on posts