# What is a sub-1 sat/vB transaction?

A transaction paying below Bitcoin Core's default floor of 1 sat/vB, which Blockspace Labs' node relays.

URL: https://blockspace.wiki/answers/what-is-a-sub-1-sat-vb-transaction/

It is a transaction paying less than 1 sat per vbyte, the default relay floor of Bitcoin Core. Blockspace Labs' node runs stock Bitcoin Core with a minrelaytxfee of 0 sat/vB (as of block 972,320, 2026-10-20 12:17:53 UTC), so it relays and keeps such transactions. This [sub-1 sat/vB relay](https://blockspace.wiki/glossary/sub-1-sat-vb-relay/) is a Live Labs project, and its mempool explorer is explore.block.space.

Sources:

- The blockspacelabs.com page (index.html) · https://blockspacelabs.com
- Blockspace Holdings records

Live figures: relay as of block 972,320, 2026-10-20 12:17:53 UTC

Updated: 2026-10-20