How to optimize performance of Bubble.io apps: Step-by-Step Guide

Go to Settings → Metrics (or the Logs tab → Workload metrics). Review the pie chart showing which activities consume the most WUs. Identify the top consumers — common culprits include complex searches, Repeating Groups with nested searches, and backend workflows processing large lists. Click into specific time periods to see spikes. The Server logs tab shows WUs charged per individual action, helping you pinpoint exactly which workflows and searches are most expensive. Focus your optimization efforts on the top 3-5 consumers first.

Option Sets are cached on the user's device and cost zero Workload Units to access. Any data that is static and does not change per user — categories, statuses, countries, feature flags — should be an Option Set instead of a Data Type. Go to Data tab → Option sets and create sets for your static data. Then update all elements that currently search a Data Type for this static data to reference the Option Set instead. For example, replace 'Do a search for Categories' with 'All Categories' (the Option Set). This eliminates database queries entirely for that data.

Repeating Groups are the most common performance bottleneck. Apply these fixes: (1) Add pagination — set a fixed number of rows (10-20) instead of showing all items. (2) Use database constraints instead of :filtered — constraints run on the server and use indexes; :filtered processes every row client-side. (3) Remove 'Do a search for' inside RG cells — each cell search multiplies queries by the number of visible cells. Instead, use Parent group's data references. (4) Pre-compute counts — if you show 'Number of comments' per post, add a Comment_Count field to the Post type and increment it in workflows instead of counting dynamically.

Bubble renders every element when the page loads, even hidden ones. To reduce page weight: (1) Remove unused elements — check the Element Tree for elements you no longer need. (2) Move complex sections into Reusable Elements — they load on demand. (3) Uninstall unused plugins — every plugin adds JavaScript to every page regardless of use. Go to Plugins tab and remove any you are not actively using. (4) Compress images — use tools like TinyPNG before uploading. Bubble's image auto-compression helps but pre-compression is better. (5) Minimize the number of groups and nested containers — flatten your layout where possible.

Move expensive operations to backend workflows where they do not block the user interface. Use 'Schedule API Workflow' to process heavy tasks asynchronously — the user sees a confirmation immediately while processing happens server-side. For bulk operations, use 'Schedule API Workflow on a list' instead of looping. Eliminate redundant workflow actions — if two actions write to the same record, combine them into one 'Make changes to a thing.' Remove 'Add a pause before next action' workarounds and use 'Result of step X' for data dependencies instead.

Store frequently accessed data in Custom States or hidden floating groups to avoid repeated searches. On page load, run your heavy searches once and store results in a Custom State — subsequent references use the cached state instead of re-querying. For data that multiple users access (like a leaderboard), consider a CachedData Data Type that stores pre-computed results with a timestamp. A scheduled backend workflow refreshes this data periodically. Users read from the cached record instead of running the expensive query on every page load.