Deploy your JavaScript app to Heroku
Step-by-step deployment help for JavaScript apps on Heroku. We fix JavaScript-specific deployment issues, configure Heroku, and get your app live. From $19.
JavaScript issues we fix before deploying
Common JavaScript problems that affect Heroku deployments.
Prototype pollution
AI-generated code merges user-supplied objects into prototypes via Object.assign or spread operators without sanitization, enabling property injection attacks.
Loose equality comparisons
Using == instead of === leads to type coercion bugs where '0' == false, null == undefined, and other non-obvious truthy/falsy comparisons cause silent logic errors.
Unhandled promise rejections
Async functions without try/catch or .catch() handlers cause unhandled rejection warnings and silent failures in production.
Global variable leaks
Missing 'const' or 'let' declarations create implicit globals that pollute the global scope and cause unpredictable behavior across modules.
Heroku deployment issues we check for
Common Heroku problems that break JavaScript apps in production.
Free dyno sleeping causes cold starts
Eco and Basic dynos sleep after 30 minutes of inactivity. AI-generated apps with webhook receivers or background jobs break when the dyno is asleep.
Ephemeral filesystem loses uploaded files
AI tools save user uploads and generated files to the local filesystem, but Heroku's ephemeral FS wipes all changes on every dyno restart or deploy.
Database connection pool exhaustion
Heroku Postgres plans have strict connection limits (20 on Hobby). AI-generated apps open a new connection per request, exhausting the pool under moderate traffic.
Procfile missing or incorrect
AI-generated projects lack a Procfile, causing Heroku to guess the start command. For non-standard setups, this guess is often wrong.
Start with a self-serve audit
Get a professional review of your JavaScript project before deploying to Heroku.
External Security Scan
Black-box review of your public-facing app. No code access needed.
- OWASP Top 10 vulnerability check
- SSL/TLS configuration analysis
- Security header assessment
- Expert review within 24h
Code Audit
In-depth review of your source code for security, quality, and best practices.
- Security vulnerability analysis
- Code quality review
- Dependency audit
- Architecture review
- Expert + AI code analysis
Complete Bundle
Both scans in one package with cross-referenced findings.
- Everything in both products
- Cross-referenced findings
- Unified action plan
100% credited toward any paid service. Start with an audit, then let us fix what we find.
How it works
Tell us about your app
Share your project details and what you need help with.
Expert + AI audit
A human expert assisted by AI reviews your code within 24 hours.
Launch with confidence
We fix what needs fixing and stick around to help.
Frequently asked questions
How do I deploy a JavaScript app to Heroku?
We handle JavaScript deployments to Heroku end to end. Start with our code audit ($19) to identify deployment blockers specific to your JavaScript project, then we configure Heroku, fix issues, and get your app live in production.
What JavaScript issues affect Heroku deployments?
JavaScript projects commonly have prototype pollution and loose equality comparisons. On Heroku, these combine with free dyno sleeping causes cold starts and ephemeral filesystem loses uploaded files to cause deployment failures.
Can SpringCode deploy my JavaScript project to Heroku?
Yes. We specialize in deploying JavaScript applications to Heroku. We audit your codebase for JavaScript-specific issues, configure Heroku correctly, and handle the full deployment so your app runs reliably in production.
What does JavaScript deployment to Heroku cost?
Our code audit ($19) identifies all Heroku deployment blockers in your JavaScript project. Full deployment assistance is scoped with a fixed quote after the audit — no hourly billing or surprise charges.
Related resources
Other techs on Heroku
Deploy JavaScript elsewhere
Need help deploying JavaScript to Heroku?
Tell us about your project. We'll respond within 24 hours with a clear plan and fixed quote.