Common signs: data lost when users clear the browser or switch devices, and analytics that don't match. Usual causes: important data saved only in localStorage. What we do: design tables, migrate and sync the data. What you get: data stored safely on the server.
Our localStorage to database migration moves important user data, such as history, progress, settings and drafts, out of the browser and into your database, where it's backed up, shared across devices and visible to your app. A Codersarts engineer designs the tables, moves existing data across and keeps it in sync. Fixed price from $199 with 1-day delivery.
localStorage to Database at a Glance
Item | Details |
|---|---|
Starting price | $199 for one type of data |
Delivery | 1 day |
Databases | PostgreSQL, Supabase, Firebase, MongoDB and MySQL |
Includes | Schema, API, migration of existing browser data and sync |
Offline | Optional offline-first sync |
What you get | Data stored safely on the server, on every device |
Revisions | One revision round included |
Why Move Data Out of localStorage?
localStorage is a small storage area inside each user's browser. It's handy for preferences, but data saved there is lost when users clear their browser, isn't available on other devices, can't be seen by your backend or analytics, and isn't backed up. Anything that matters, such as progress, history or saved work, belongs in a database.
Signs Your Data Belongs in a Database
Users lose progress or history when they clear their browser or switch devices
Leaderboards or analytics disagree with what users see
Streaks, scores or saved work are calculated in the browser
Admins can't see user data that only exists in browsers
You're hitting localStorage size limits
Why Data Ends Up in localStorage
Quick prototypes
It was the fastest way to save data during early development.
AI-generated code
AI builders often default to localStorage.
No backend yet
The app started without a database for that feature.
Offline needs
Data was kept locally to work offline, without a sync plan.
Quick Checks You Can Try First
Open your browser's developer tools and list what's stored in localStorage.
Mark which items users would be upset to lose.
Check whether your database already has a table for that data.
Stop storing sensitive data, such as tokens or personal details, in localStorage.
If the problem remains, our engineers take it from there.
How We Move Your Data
Audit. We list everything stored in localStorage and what it's used for.
Design. We design tables with ownership and access rules.
Build the API. We add endpoints or database calls to save and load the data.
Migrate. We move existing browser data to the server on users' next visit.
Sync. We keep browser and server in sync, with offline support if needed.
Test. We test that nothing is lost across devices and sessions.
What You Get
Database tables with access rules
Save and load logic in your app
Automatic migration of existing browser data
Sync across devices
Tests confirming data isn't lost
Example result (illustrative)
A coding practice app stored 300 to 400 lines of code history per user in localStorage, and streak counts differed between the profile and the leaderboard. We moved history and streaks into Supabase with row-level security, migrated existing data on next login, and both screens now read the same numbers.
What Is Included and Not Included
Included | Not included |
|---|---|
One type of data, such as history or progress | Rebuilding the whole app's data layer |
Schema, API, migration and sync | Changing your database provider |
Access rules for the new tables | Large offline-first apps (higher package) |
One revision round | Ongoing data maintenance |
Pricing for localStorage Migration
Package | Best for | Starting at | Delivery |
|---|---|---|---|
Storage audit | List what's stored and what should move | $29 | 24 hours |
Data migration | Move one type of data to the database with sync | $199 | 1 day |
Full migration | Several data types plus offline sync | $599 | 3 days |
You get a fixed quote after we review your setup. You approve the scope before any payment.
Who This Is For
Apps built quickly or with AI tools
Learning and practice platforms tracking progress
Products where users switch devices
Teams fixing mismatched leaderboards or analytics
What We Need From You
Repository access
Your database and hosting details
Which data users must never lose
A test environment
Code and data privacy
We sign an NDA on request, work with the least access needed, and never keep copies of your data after delivery. You own all code, configuration and notes.
Key Terms Explained
localStorage: a small storage area in each user's browser
Sync: keeping data the same between browser and server
Row-level security: database rules that limit each user to their own rows
Offline-first: an app that works offline and syncs when back online
Common Mistakes We Avoid
Deleting browser data before confirming it's saved on the server
Storing tokens or personal data in localStorage
Calculating scores in the browser where users can change them
Forgetting access rules on the new tables
Need More Than One Task?
Need a wider database cleanup or migration? See Database Migration and Schema Design. Or use Prepaid Developer Hours to cover several tasks from one prepaid balance.
Related Tasks
Backup & Restore Setup so the new data is backed up
Playwright E2E Test Setup to test data across sessions
Redis Caching Setup for fast reads of shared data
Frequently Asked Questions
Is it bad to use localStorage?
No, for small preferences such as theme or language. Data that matters should live in a database.
Will users lose their existing data?
No. We migrate existing browser data to the server on the user's next visit before removing it locally.
Can it still work offline?
Yes. With offline-first sync, data is saved locally and synced when the user is back online.
Which database should I use?
Usually the one you already have. Supabase, PostgreSQL and Firebase all work well.
Keep Your Users' Data Safe
Share your app and what's stored in the browser, and a Codersarts engineer will move it into your database without losing anything.