nostr.build logoblossom.band
Nostr · Blossom server

Your own Blossom server. Your own domain.

Free uploads for everyone, from any Blossom-capable client. A plan gives you a dedicated name.blossom.band of your own — backed by the infrastructure nostr.build has run since 2022.

What you get

Nostr.build's Blossom server

Backed by time-proven, highly available infrastructure with global reach and a fast CDN. Every distinct npub gets its own server domain, not shared with anyone but its owner.

Limits

Generous & flat

A hard cap of 100 MiB per upload (20 MiB for free uploads), with no limit on the number of uploads or retention. Need more? See the plans.

Media

All the common types

Free uploads support images, audio and video — .jpg, .png, .webp, .gif, .mp4, .mov, .wav, .mp3, .flac and many more. With a plan you also get .pdf, .svg and .zip.

Privacy

Metadata stays private

Media containing GPS metadata is rejected from PUT /upload and PUT /mirror. All uploads are subject to our Terms of Service.

Plans

Real prices, paid once a year in Bitcoin

Two- and three-year terms cost less per year. Checkout, upgrades and renewals all happen at account.nostr.build.

Free vs paid

What free gives you, and what a plan adds

Free, forever
  • Uploads up to 20 MiB per file
  • Images, audio and video
  • No limit on how many files, and no expiry
  • Global CDN delivery with on-the-fly image resizing
  • GPS metadata rejected, never stored
With a plan
  • Uploads up to 100 MiB per file
  • Your own subdomain, not shared with anyone
  • PDF, SVG and ZIP on top of the free types
  • Storage that counts against your plan, managed from your dashboard
  • Your own Nostr relay, included with the same plan
The other half

A plan also gives you your own Nostr relay

Blossom holds your media; relay.nostr.build holds your notes. Unlimited events with no expiry, one-click import of your history from your old relays, DMs served only to the people in them, and your public notes pushed out to the wider network for you. It is included with the same plan — no separate purchase.

Endpoints

Authentication is a signed nostr event; file metadata follows NIP-94 (BUD-08).

GET /<sha256>auth optionalBUD-01
HEAD /<sha256>auth optionalBUD-01
PUT /uploadauth requiredBUD-02
HEAD /uploadauth requiredBUD-06
PUT /mediaauth requiredBUD-05
HEAD /mediaauth requiredBUD-05
PUT /mirrorauth requiredBUD-04

Limited by the remaining storage in the account, or 20 MiB for free uploads.

DELETE /<sha256>auth requiredBUD-02
GET /list/<pubkey>auth requiredBUD-02
Responsive images

Resize images on the fly

Add a ?w= query to any image link and it serves a smaller, CDN-resized variant in the most efficient format the client supports. Pass a pixel width — ?w=720 or ?w=720px — or a named resolution — ?w=720p. The value rounds up to the nearest of five sizes (240p, 360p, 480p, 720p, 1080p), clamped at the ends.

GET /<sha256>.jpg?w=720

Works on images; other types serve the original unchanged.

Questions worth asking
Do I need a plan to use this?

No. Free uploads work from any Blossom-capable client with a signed Nostr event, and they are not going away. A plan raises the per-file limit, adds document types, and gives you a subdomain of your own.

What happens to my files if my plan lapses?

Your uploads are not deleted the moment a plan expires. What you lose is the ability to keep uploading at paid limits. If you would rather leave, everything you uploaded is addressed by its SHA-256 hash and can be mirrored to any other Blossom server.

Is my subdomain really mine?

Yes — a claimed hostname maps to exactly one npub, and nobody else can upload to it. You can change which hostname you use from your dashboard.

Where are the files actually stored?

On nostr.build's own infrastructure, the same storage and CDN that has served Nostr's media since 2022 — not a reseller layer over somebody else's bucket.

About

nostr.build started as a free, community-focused media uploader for Nostr on December 24, 2022. Our purpose is to help grow the Nostr ecosystem with a free, web-based, API- and application-integrated way to upload media. We believe in a transparent, community-based approach to moderation and open-source code — a small team of developers and designers passionate about the decentralized internet, committed to a safe and secure platform and always open to feedback.