What is Log?
A timestamped message your app writes to record what it's doing.
In plain English
A log is a message your app writes to record what's happening. For example: 'User 1234 logged in', 'API call to /api/orders took 450ms', 'Database query failed: connection timeout'. Logs have a timestamp, a level (DEBUG, INFO, WARN, ERROR), and a message. When something breaks, you read the logs to find out what happened. console.log() is the simplest form of logging — but production apps use structured logging (JSON format) so logs can be searched and filtered. FlareLog auto-captures console.log and adds structured logging via the SDK.
Why it matters
Without logs, you're debugging blind. When a user says 'your app is broken', you have no way to see what happened on their request. Logs let you trace exactly what your app did — which functions ran, which API calls were made, which database queries executed, and where the error occurred. For vibe-coded apps, logs are especially valuable because they tell you what the AI-generated code is actually doing at runtime.
How FlareLog handles it
FlareLog auto-captures console.log, console.error, console.warn — so even if you didn't add any logging, you'll still see output. The SDK adds structured logging with traceId, userId, and custom metadata. Logs are searchable by level, source, message, and metadata fields. Retained for 90 days on Pro.
FAQ
What's the difference between console.log and FlareLog?
console.log prints to your terminal (in dev) or disappears (in production on Workers). FlareLog captures console.log output AND ships it to a dashboard where you can search, filter, and retain it. In production, you can't see console.log without a logging tool — FlareLog is that tool.
How many logs should I generate?
Log what matters: errors (always), warnings (usually), info (for key events like 'user signed up'), debug (only in development). Don't log every request — that's what metrics are for. FlareLog's free tier includes 10k logs/month, which is plenty for a small app. Pro gives you 2M/month.