How do you protect a premium theme from being copied?

There is no way to prevent the free distribution of your theme. You could make it harder by selling a copy that is restricted to a license key and a salted hash of the domain. But even if you put the code for this in a pre-compiled script it will be possible to get around it.

Sell support, upgrades and reliability, not the naked code.

For the license: PHP code which is uses WordPress functions and hooks is GPL per default by some peoples interpretation.
For your stylesheets, images and standalone PHP code you can use a different license.

Related Posts:

  1. Is accessing theme and using customizer GPL distribution?
  2. WP 3.4 – what action/hook is called when theme customisation is saved?
  3. Add a dropdown to theme customizer
  4. Is it good to rename theme folder downloaded from WordPress.org?
  5. Editing the custom background CSS
  6. What is the problem if I use CDN in my WordPress parent theme(built using bootstrap)?
  7. Is it possible to use line break in theme description?
  8. How can I get wp_head() as a string instead of echoing it?
  9. Grab the first paragraph of each post
  10. How to check if post has any tag?
  11. What are WooCommerce starter themes? [closed]
  12. How do I “unhook” / de-register jQuery so that it’s not called as part of wp_footer();?
  13. How to disable the gradient and font size internal CSS added by WordPress when using theme.json
  14. Example of a theme organization without all the default wp files in root
  15. Which is the simplest theme for WordPress to use it as your base?
  16. “Cheatin’ uh?” error message on multple theme directories
  17. Adding WordPress colorpicker in widget settings
  18. Disable the Custom Internal CSS added by theme.json for Certain Pages
  19. Unwanted blank lines before tag
  20. A theme that follows all the best practices to learn from?
  21. How do I display the “Archives” widget layout (sidebar) in WordPress by ‘year’ then by ‘months’?
  22. get_post() function returns post even if it is trashed
  23. How to highlight the current page in the nav menu?
  24. What page should I use for a contact form?
  25. Retrieve data using wpdb to use for customizer controls
  26. Custom Nav Walker Displaying Values in Sub Menu
  27. How to configure wordpress to work with Vuejs with SSR and without hashbang
  28. How can one update a theme on a live site without interruption?
  29. Sub folder CSS that’s read by Admin panel
  30. Some doubts about how to show posts in a custom theme?
  31. Dequeue a style file which is making website load slow!
  32. How to remove a file included in parent theme with locate_template() via child theme?
  33. Can’t delete theme
  34. How to add a second stylesheet to the editor
  35. Stylesheet not linking
  36. How to control layout of posts on page?
  37. Override template file i subfolders
  38. Single Page theme [closed]
  39. Theme Development for WordPress Multisite Installation
  40. Can I have two different theme for two different language?
  41. create category on theme setup
  42. WP_Comment_Query – Get comments and answers separately
  43. excerpt() shows different result between remote and localhost(development environment)
  44. Prefix best practice, should we use framework name or theme name?
  45. Theme Javascript.php Overwritten Nightly [closed]
  46. WordPress get_template_part() function not working
  47. How to add Space between sidebar and footer widget in WordPress theme [closed]
  48. Call to undefined function add_menu_page() on theme activation
  49. Best way to develop a new theme on a live site, with new content? [closed]
  50. How do I make the most minimal vanilla theme possible with nothing but raw content?
  51. Can I Set Up Session in WordPress Custom Page
  52. Is it acceptable for a WordPress theme to not accept widgets?
  53. Should all references to a text domain be to my current theme?
  54. How can I hard code my sidebar?
  55. Simple child theme modification but links are broken
  56. Making a WordPress theme based on twentyten
  57. How can I wrap all blog posts image with
  58. theme style is applied on the dhasboard rather than the website
  59. Alignment Problem [closed]
  60. What $handle does WordPress use for a theme’s implicit style.css?
  61. Issue when posting updates/changes to wordress
  62. StoreFront WordPress theme: How can i create a new Home page with Custom design same as template [closed]
  63. A post with a clear:both in its css destroy the theme design, and the sidebar is moved to the bottom
  64. Unwanted empty line at the beginning of document
  65. Why is my container argument not working for wp_nav_menu() [closed]
  66. Never actually adding the action? Or do I have to call the action?
  67. best practices for updating wordpress theme
  68. How to hide custom sidebar on mobile
  69. help needed for suit designing tool
  70. How to modify theme content in Thematic?
  71. How to update mark-up of a gallery block in a custom theme?
  72. Host Private Custom Theme
  73. My wordpress theme name isn’t updating straight away
  74. Customizer API Multi Sections in single Panel
  75. WordPress theme options checkbox default checked state
  76. Copying a modified theme from one wordpress site to another wordpress site [closed]
  77. How can I change this SVG shape that’s generated?
  78. Adding a second logo next to the main one in header
  79. How can I not disable my theme when I want to upload a new version of it?
  80. (Parent) theme Is Not Showing In Theme Selection Panel and Therefore Breaks Child Theme
  81. How can I fix my theme header for my CSS stylesheet?
  82. Is hand coding required at all?
  83. How to show some of category in wordpress
  84. using themename_the_custom_logo() in template-tags?
  85. Creating a theme just to deploy a single page
  86. Creating a Sub Category Template
  87. Custom page template not showing on page creation
  88. how can I re-utilize and class on a child theme
  89. Weird ‘theme update’ error [duplicate]
  90. Incorrect search results in search.php – issue triggered by using `define(‘BodyID’, ‘search’); the_post();` in search.php
  91. Flexslider not working for my custom theme WordPress
  92. WordPress two sidebar layout or theme
  93. Standard Way To Do Custom Work Within A Page?
  94. Confused on loading page content
  95. Add Dynamic Sidebar to Exisiting WordPress Theme [closed]
  96. How can I install my custom-made theme on a wordpress.com blog? [closed]
  97. Turning WordPress Into full-featured website?
  98. Why am I getting posts back when I shouldnt
  99. .submenu class missing in output from wp_nav_menu
  100. What is the point of using the front-page.php template? [closed]
techhipbettruvabetnorabahisbahis forumueduedueduseduedueduedueduedusedu