console

January 18, 2026 · View on GitHub

Standard JavaScript-style logging functions. Output is displayed in the Console tab.

Availability: Both (pre-request and post-response)

For the complete API reference, see Scripting API Reference.

Overview
Quick Reference
Methods
Examples
See Also

Overview

The console object provides familiar logging functions like those in browser JavaScript:

Log messages at different severity levels
Output is captured and displayed in the Console tab
Supports multiple arguments and object formatting

Quick Reference

Method	Description
`log(args...)`	General logging
`info(args...)`	Informational messages
`warn(args...)`	Warning messages
`error(args...)`	Error messages
`debug(args...)`	Debug messages

Methods

log(args...)

General-purpose logging. Outputs to the Console tab.

console.log("Request sent successfully");
console.log("User:", userName);
console.log("Count:", 42, "items");

info(args...)

Informational messages. Same output as log() but semantically indicates informational content.

console.info("Processing started");
console.info("Found", items.length, "items");

warn(args...)

Warning messages. Use for non-critical issues that should be noticed.

console.warn("Rate limit approaching");
console.warn("Deprecated API version detected");
console.warn("Missing optional field:", fieldName);

error(args...)

Error messages. Use for failures and exceptions.

console.error("Request failed");
console.error("Invalid response format:", response.status);
console.error("Missing required field: api_key");

debug(args...)

Debug messages. Use for detailed debugging information.

console.debug("Request headers:", headers);
console.debug("Parsed body:", JSON.stringify(body, null, 2));

Output Formatting

Multiple Arguments

All methods accept multiple arguments, which are concatenated with spaces:

console.log("User:", userName, "- ID:", userId);
// Output: "User: John - ID: 123"

Objects

Objects are automatically JSON-formatted:

console.log({ name: "John", age: 30 });
// Output: {"name":"John","age":30}

// For pretty-printing
console.log(JSON.stringify(data, null, 2));

Arrays

Arrays are displayed in JSON format:

console.log([1, 2, 3]);
// Output: [1,2,3]

Examples

Basic Logging

// Pre-request: Log request info
console.log("Sending request to:", lc.request.url);
console.log("Method:", lc.request.method);
console.log("Headers:", lc.request.headers.all());

Response Logging

// Post-response: Log response details
console.log("=== Response ===");
console.log("Status:", lc.response.statusText);
console.log("Time:", lc.response.time, "ms");
console.log("Content-Type:", lc.response.headers.get("Content-Type"));

Conditional Logging

// Post-response: Log based on status
if (lc.response.status === 200) {
    console.info("Request successful");
} else if (lc.response.status >= 400 && lc.response.status < 500) {
    console.warn("Client error:", lc.response.status);
} else if (lc.response.status >= 500) {
    console.error("Server error:", lc.response.status);
}

Debug Data Flow

// Pre-request: Debug data transformation
var originalBody = lc.request.body.json();
console.debug("Original body:", originalBody);

// Transform
var transformed = {
    ...originalBody,
    timestamp: Date.now()
};
console.debug("Transformed body:", transformed);

lc.request.body.set(JSON.stringify(transformed));

Structured Logging

// Post-response: Structured log entry
var logEntry = {
    timestamp: new Date().toISOString(),
    request: {
        method: lc.request.method,
        url: lc.request.url
    },
    response: {
        status: lc.response.status,
        time: lc.response.time
    },
    environment: lc.info.environmentName
};

console.log("Request Log:", JSON.stringify(logEntry, null, 2));

Error Handling with Logging

// Post-response: Detailed error logging
if (lc.response.status >= 400) {
    console.error("=== Error Details ===");
    console.error("Status:", lc.response.statusText);
    console.error("Endpoint:", lc.request.url);

    var errorBody = lc.response.body.json();
    if (errorBody) {
        console.error("Error Code:", errorBody.code);
        console.error("Error Message:", errorBody.message);
        if (errorBody.details) {
            console.error("Details:", JSON.stringify(errorBody.details, null, 2));
        }
    } else {
        console.error("Raw Body:", lc.response.body.raw());
    }
    console.error("=====================");
}

Progress Tracking

// Pre-request: Log progress in collection runs
console.info("=== Request", lc.info.iteration, "of collection ===");
console.info("Collection:", lc.info.collectionName);
console.info("Request:", lc.info.requestName);
console.info("Environment:", lc.info.environmentName);

Performance Logging

// Post-response: Performance analysis
var time = lc.response.time;

if (time < 200) {
    console.log("Performance: Excellent (" + time + "ms)");
} else if (time < 500) {
    console.info("Performance: Good (" + time + "ms)");
} else if (time < 1000) {
    console.warn("Performance: Acceptable (" + time + "ms)");
} else {
    console.error("Performance: SLOW (" + time + "ms)");
}

Variable Inspection

// Pre-request: Inspect environment variables
console.log("=== Environment Variables ===");
var vars = lc.env.toObject();
for (var key in vars) {
    // Mask sensitive values
    var value = vars[key];
    if (key.toLowerCase().includes("secret") || key.toLowerCase().includes("password")) {
        value = "****";
    }
    console.log(key + ":", value);
}