Observe
Logs
Your app's output and each deployment's log, live in the console.
Open a service's Logs to see what it writes to standard output and standard error, live.
- All, Deploy and App switch between everything, the deployment's own messages and your app's output.
- Filter logs keeps the lines that contain a text.
- Pause stops the view from moving while you read; Resume follows again. The view updates every two seconds.
| Kept for | 7 days |
| Per deployment | the last 5,000 lines |
| One line | up to 2,000 characters |
| Build logs | 30 days, in Builds |
Values of your variables are masked in logs. See Variables.
Write logs as one line per event, and JSON if you search them a lot: a line holds up to 2,000 characters, and a multi-line stack trace is easier to find when it stays on one line.