Most blogs on Tumblr have a single author or a small group of approved writers, but some thrive on user submissions, aggregating writing, photos and other content from loyal fans. Not every blog that takes submissions accepts every type of media, and there's no guarantee the blog owner will post your submission, but both the Tumblr app and Tumblr website provide an avenue for sending your pictures.
Submissions won't show up on the blog right away. The blog's owner or another blog administrator has to accept your submission before you'll see it.
Visit the blog you want to submit to, tap the mail icon and choose Submit. If you don't see the Submit option, or if there's no mail icon, the blog does not take submissions.
Tap Photo. If Photo is grayed out and doesn't work, the blog doesn't accept picture submissions.
Tap each picture you want to submit, in order, or tap Camera to take a new photo. Press Next after selecting all the images you want to use.
Enter a caption for your photos if you want, and then tap Submit.
Visit the Tumblr blog you want to contribute to and click the Submit link.
The default blog style places the Submit link right below the title, but the blog's owner can move it elsewhere or change the link's text, so check lower on the page or in the sidebar if you don't see it. If there isn't a link anywhere, you can't submit to that blog.
Open the Text drop-down menu and choose Photo to switch post types. If Photo isn't in the list, the blog doesn't take image submissions.
Click Choose a Photo and pick an image file on your computer, or drag the file from your computer onto the page.
Type a caption if you want one, check the box to accept the terms of submission and click Submit.