Tumblr Theme Asset File Limits: If you have images, stylesheets or JavaScript to customize your blog theme, Tumblr allows you upload a maximum of 15 megabytes of static files per day. There is also a limit of 5 megabytes per static file.
To upload static files as theme assets, click Customize from the Desktop Dashboard. The Edit Theme page appears. Click Edit HTML. You’ll see the HTML for your theme. In the upper left, click the gear icon and, from the drop-down menu, select Theme Assets. The Theme Assets panel appears. Click Add a File.
These static files must be for your blog theme. Uploading anything else can get your Tumblr account banned.












