Why is my Lovable app slow? How to find it and speed it up
Why a Lovable app slows down as it grows (too many queries, missing indexes, heavy images, a small instance) and how to measure each before fixing it.
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A Lovable app usually gets slow because of how it asks for data, not because of where it's hosted. The common causes are pages that make dozens of separate database requests, lists that load every row at once, filters on columns without an index, and large images. A too-small backend instance is real but comes last on the list. Measure which part is slow first, because each cause has a different fix and guessing wastes credits.
Below: how to tell what kind of slow you have, the tools that show the cause (some built into Lovable), a fix for each cause, and how to confirm the improvement.
What kind of slow is it?
"The app is slow" covers very different problems. Pin down which one you have:
- The first visit takes long to show anything. That's loading: bundle size, images, fonts.
- One page always spins for seconds. That's usually that page's data requests.
- It used to be fast and got slower as you got users. That's queries that scale with data: no pagination, no indexes.
- Everything slows down at busy times. That may be the database instance.
- Typing or scrolling feels sticky. That's the browser doing too much work, often components re-rendering.
Write down the exact page and action, and time it. You'll need that number to know if a fix worked.
How do I measure it?
For loading speed
Run the page through Google's PageSpeed Insights. It reports Core Web Vitals and lists the heaviest resources. If the biggest items are images of several megabytes, start there. Our guide to Core Web Vitals for an AI-built app explains what the scores mean.
For slow pages
Open the browser's developer tools, go to the Network tab, and reload the slow page. Look at two things: how many requests go to your backend (addresses with /rest/v1/), and how long each one waits. Forty requests on one page, or requests that start only after the previous one finished, are the pattern to look for.
Inside Lovable
Lovable has two tools worth using before any code change, both in Plan mode so nothing is modified:
The app works but feels sluggish. Analyze the project for performance bottlenecks and report without changing any code.My app feels slow. Find the slowest database queries and optimize the worst ones.The second one reads your database's query statistics and ranks queries by total time. It needs real traffic to have something to report, so it's less useful on a brand-new app.
On the built-in backend, More → Cloud → Overview → Advanced settings shows CPU, Memory and Disk cards for the last 24 hours, with highlighted hours when the database was near its limit.
How do I fix each cause?
| What you found | Cause | Fix |
|---|---|---|
| Dozens of requests per page, one per item | A query per row (the "N+1" pattern) | Fetch related data in one query |
| Lists slow down as data grows | Loading every row | Paginate |
| Filters and searches are slow | No index on the filtered columns | Add indexes |
| First visit slow, large files in Network | Heavy images or bundle | Resize and compress images, split routes |
| Pressure in the CPU or Memory cards | Instance too small, or one bad query | Fix queries first, then resize |
One query instead of fifty
AI-generated code often loads a list, then loops over it and loads each item's details separately. With the Supabase client, related tables can come back in one request:
const { data } = await supabase
.from("orders")
.select("id, total, created_at, customer:customers(name, email)")
.order("created_at", { ascending: false })
.range(0, 49);That single request replaces one for the orders plus one per customer.
Paginate lists
Supabase's API returns at most 1,000 rows per request by default (a project setting), so an app that "loads everything" is both slow and, past that point, silently incomplete. Load 25 or 50 at a time with .range() and add a "load more" button or pages.
Add indexes where you filter
A filter on a column without an index makes the database read the whole table. That's invisible with 200 rows and painful with 200,000. Supabase's row level security guide recommends an index on every column your security policies filter on, typically user_id or organization_id, and writing (select auth.uid()) instead of auth.uid() in policies so the value is computed once per query instead of once per row. Both are cheap changes with large effects on big tables. For the concept in plain words, see slow database queries and indexes, explained.
Make images smaller
A 4,000-pixel photo shown in a 400-pixel card is the most common loading problem in app dashboards and landing pages. Resize on upload, serve modern formats, and lazy-load images below the fold. Our guide to optimizing images in your web app has the details.
Resize the instance last
If the CPU or Memory cards show pressure and the queries are already fixed, a larger instance helps. In Advanced settings, Database size → Manage lets paid plans choose from Tiny up to X-Large, with an estimated monthly credit cost for each size. A resize takes a few minutes, with a brief interruption while the instance restarts. Lovable's docs say it too: check whether slow queries are the real cause before upgrading, because a bigger instance only makes a bad query fail more slowly.
How do I confirm it's faster?
Repeat the measurement you took at the start: same page, same account, same network. Compare the number of requests, the slowest request's time and the PageSpeed score. If the number didn't move, the fix targeted the wrong cause, and it's better to revert than to keep code that adds complexity for nothing.
How do I keep it fast as it grows?
- Paginate every list from the start, even when you have ten rows.
- Index the columns you filter, sort and join on, especially in security policies.
- Ask for the data a page needs in one request, and nothing more.
- Check the slowest queries once a month, or after a big feature.
The bigger picture of what breaks as usage grows is in scaling from 100 to 10,000 users.
Quick answers
Is Lovable hosting slow? Hosting is rarely the bottleneck. Measure first: most slowness comes from data requests and images.
Should I upgrade the Cloud instance? Only after checking queries. If the pressure cards stay red after fixing them, then resize.
Why did my app get slow only recently? Usually because data grew. Queries without pagination or indexes get slower with every row.
Want someone to profile it?
If you've measured and the cause still isn't clear, a code review usually finds the two or three changes that matter most. Run the free health check, see how we fix Lovable apps, or tell us which page is slow.
