Import
import { logger } from 'hono/logger'
Usage
const app = new Hono()
app.use(logger())
app.get('/', (c) => c.text('Hello Hono!'))
Options
The logger middleware accepts an optional print function:
fn
(str: string, ...rest: string[]) => void
default:"console.log"
Optional function for customized logging behavior. This function will be called with the formatted log message.
Signature
logger(fn?: PrintFunc): MiddlewareHandler
Examples
Basic usage
const app = new Hono()
app.use(logger())
app.get('/', (c) => c.text('Hello Hono!'))
// Logs:
// --> GET /
// <-- GET / 200 5ms
Custom print function
import { logger } from 'hono/logger'
app.use(logger((message) => {
console.log('Custom:', message)
}))
Log to file
import fs from 'fs'
const logStream = fs.createWriteStream('app.log', { flags: 'a' })
app.use(logger((message) => {
logStream.write(message + '\n')
}))
Structured logging
app.use(logger((message) => {
const logEntry = {
timestamp: new Date().toISOString(),
message,
}
console.log(JSON.stringify(logEntry))
}))
Conditional logging
const isDevelopment = process.env.NODE_ENV === 'development'
if (isDevelopment) {
app.use(logger())
}
Apply to specific routes
const app = new Hono()
// Only log API routes
app.use('/api/*', logger())
app.get('/api/users', (c) => c.json({ users: [] }))
- Incoming request:
--> METHOD PATH
- Outgoing response:
<-- METHOD PATH STATUS DURATION
Examples
--> GET /api/users
<-- GET /api/users 200 12ms
--> POST /api/users
<-- POST /api/users 201 45ms
--> GET /not-found
<-- GET /not-found 404 3ms
Status Code Colors
When color is enabled (supported terminal), status codes are color-coded:
- 2xx (Success): Green
- 3xx (Redirect): Cyan
- 4xx (Client Error): Yellow
- 5xx (Server Error): Red
Behavior
- Logs incoming request before handler execution
- Logs outgoing response after handler completes
- Includes response status code and elapsed time
- Time is displayed in milliseconds for durations < 1 second
- Time is displayed in seconds (rounded) for durations >= 1 second
- Automatically detects color support in terminal
- Works with all HTTP methods
- Extracts path from full URL for cleaner logs
