Short answer
Open the organization’s Usage page and the Upcoming Invoice on the billing page, then pick each project from the dropdown to see which one grew. Compute is billed per project by the hour and is not covered by the Spend Cap, so an extra project, a bigger compute size, branches or read replicas add to the bill on their own. For usage lines such as egress or realtime messages, find the query or listener sending too much data and fix that first. Then delete projects you don’t use.
Rather not fix it yourself? App Fix Ticket starts with a fixed-price diagnosis, then a fixed price for the fix before any fix work.
Where the money goes, and the fix
01
Find the line and the project
“The page shows the usage of all projects by default. To view the usage for a specific project, select it from the dropdown.” Supabase, Manage Compute usage
Usage is summed across every project in the organization into one invoice, so start with the Usage page, then pick each project from the dropdown. The Upcoming Invoice section estimates the full cycle from usage so far.
02
Every project adds compute
“Each project you launch increases your monthly Compute costs.” Supabase, About billing on Supabase
Each project runs on its own server, billed by the hour while the project is running, whether or not anyone uses it. The Compute Credits included in paid plans cover one project on the Micro or Nano size, so a second project, a staging copy or a bigger compute size is new spend. Read Replica and Branching compute are not covered by the credits either.
03
The Spend Cap doesn’t cover compute
“Compute Hours are not covered by the Spend Cap.” Supabase, Manage Compute usage
With the Spend Cap on, covered usage items stop at the plan quota until the next billing cycle. Compute is not one of them, and neither are items you opted into yourself, so the cap can be on while the bill still grows.
04
The Spend Cap is off
“Any additional usage will be charged based on the item's cost per unit, as outlined on the pricing page.” Supabase, Cost control
With the cap off, the app keeps running past the quota and each extra unit is billed. That keeps the app up, so watch the usage page.
05
Queries send too much data out
“Reduce the number of fields or entries selected when querying your database” Supabase, Manage Egress usage
Egress is the data your project sends to the app, charged per gigabyte over the quota. A screen that loads whole tables or every column, or repeats the same call, grows it. Select only the fields and rows the screen shows, and cache what doesn’t change.
06
Realtime listeners multiply messages
“Each database change counts as one message per client that listens to the event.” Supabase, Manage Realtime Messages usage
Realtime bills each message, and one database change is a message for every client listening to it.
Checked against the vendor’s docs on : Supabase docs: About billing on Supabase; Supabase docs: Cost control; Supabase docs: Manage Compute usage; Supabase docs: Manage Egress usage; Supabase docs: Manage Realtime Messages usage; Supabase docs: Manage Monthly Active Users usage.
Rather hand it over?
Fixed scope, fixed price, paid upfront. The work happens in writing; no call needed.
- from $450App Fix TicketOne reproducible bug in an existing mobile or web app, diagnosed and fixed.See scope and start
- from $450AI-Built App RescueA Lovable, Bolt or Cursor app checked end to end in 3 days, then its worst problems fixed at a fixed price.No issues worth fixing, no charge. If the Launch Check finds nothing rated medium or higher, Simon refunds the full $450. You keep the report either way. This applies to the first 10 Launch Checks bought after October 30, 2026.See scope and start
“Very responsive, attentive to fixing bugs, and completed the project as needed! Thank you!”
Related: Supabase app slow · Supabase project paused · Firebase bill spike · Supabase realtime not receiving changes