Schedule posts to Tumblr with LazyRelay

LazyRelay schedules text, photo and video posts to your Tumblr blog, then reads each post back from Tumblr to confirm it is live. LazyRelay's difference is Proof-of-Publish: after a post goes out, it checks Tumblr again to confirm the post is really live.

What you can post to Tumblr

Text: Tumblr publishes no post length limit that LazyRelay could verify, so this page does not state one (not verified). LazyRelay itself refuses posts over 5000 characters.
Text-only posts are accepted.
Images: JPEG, PNG, GIF, up to 20 MB each.
Video: MP4, MOV, up to 500 MB, duration limit not verified. This is a working number from an older Tumblr endpoint and is not verified for the current post format.
Several files in one post: up to 10 images (no video in a multi-image post).

LazyRelay checks file size and format before a post is scheduled and tells you which limit was hit. For the full comparison of what each platform supports, see What Works on Which Platform.

How to connect Tumblr

Sign in to LazyRelay and open the Social Platforms tab in the top menu.
Click the Tumblr tile.
Sign in to Tumblr when asked, and approve all of the permissions LazyRelay requests. Approving only some of them can make posting stop working later.
You land back in LazyRelay with the account connected. If you are logged in to several accounts on that platform in the same browser, log out of the ones you do not want first, so LazyRelay does not connect the wrong one.
A Tumblr login can cover several blogs, but each connected account posts to a single blog. If you run more than one blog, check which one is connected before you rely on it.

How Proof-of-Publish works on Tumblr

After Tumblr accepts the post, LazyRelay asks Tumblr for that post using the blog name and post ID it saved, and only marks the post confirmed live when Tumblr returns it. The link you can share is the post address Tumblr gives back.

Want the general idea? Read Does Your Post Actually Publish?

Limits and things to know

LazyRelay did not find a published Tumblr source for its limits, so every figure above is LazyRelay's own working number, not something Tumblr documents.
Tumblr's own limits are not verified, and LazyRelay does not add a cap of its own.

Schedule to Tumblr and know it actually went live.

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Frequently asked questions

Can I post to more than one Tumblr blog?

A Tumblr login can cover several blogs, but each connected account posts to one blog. Check which blog is connected before you rely on it.

Can LazyRelay schedule Tumblr photo and video posts?

Yes. Photos, GIFs and video are accepted, and a multi-image post can hold up to 10 images. The video size figure is not verified for Tumblr's current post format.

Is there a Tumblr text length limit?

Tumblr publishes no limit that LazyRelay could verify, so this page does not state one. LazyRelay itself refuses posts over 5000 characters.

How do I know my Tumblr post is really live?

LazyRelay reads the post back from Tumblr after sending it and marks it confirmed live only when Tumblr returns it.

Figures on this page come from LazyRelay's platform rules, checked on 2026-09-30. No published source was found for Tumblr's limits, so anything marked not verified is LazyRelay's own working number.

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