Comparison

This page provides a comprehensive comparison between Logly.zig and other Zig logging libraries, including the standard library's logging functions.

Feature Comparison

Logly.zig vs Other Zig Logging Libraries

Feature	logly.zig	nexlog	log.zig	std.log
Current Version	0.1.1	0.7.2	0.0.0	Built-in
Min Zig Version	0.15.0+	0.14, 0.15-dev	0.11+	Any
API Style	User-friendly	Builder/Fluent	Pool/Fluent	Basic/Manual
Structured Logging	✅ Automatic	✅ JSON/logfmt	✅ JSON/logfmt	❌ Manual
File Formats (.json, .txt, .log)	✅ Automatic	✅	✅	❌
Async Logging	✅ Automatic (ring buffer, workers)	⚠ Basic	❌	❌
Thread Safety	✅ Automatic	⚠ Partial	⚠ Pool-only	✅ Basic
Single/Multi-Thread Support	✅	❌	❌	✅ Manual
Multiple Sinks	✅ Automatic	✅	⚠ Limited	❌
File Logging	✅ Automatic	✅	✅	❌ Manual
File Rotation	✅ Automatic (Time + Size)	✅ Size	❌	❌
Retention Policy	✅ Automatic	❌	❌	❌
Compression	✅ Automatic (gzip/zlib/zstd)	❌	❌	❌
Network Logging	✅ Automatic (TCP/UDP)	❌	❌	❌
Stack Traces	✅ Automatic	❌	❌	❌ Manual
Redaction (PII)	✅ Automatic	❌	❌	❌
Sampling/Rate Limit	✅ Automatic	❌	❌	❌
Distributed Tracing	✅ Automatic (Trace/Span/Correlation IDs) + Callbacks	⚠ Context only	❌	❌
Metrics	✅ Automatic	❌	⚠ Prometheus	❌
System Diagnostics	✅ Automatic	❌	❌	❌
Filtering	✅ Automatic	❌	❌	✅ Manual
Scheduled Cleaning	✅ Automatic	❌	❌	❌
Dynamic Path	✅ Automatic	❌	❌	❌
Module-level Config	✅	❌	❌	✅ Manual
Custom Log Levels	✅	❌	❌	❌
Rules System (v0.1.0+)	✅ Template-triggered messages	❌	❌	❌
Bare-Metal Support	✅	❌	❌	✅
Prebuilt Libraries	✅	❌	❌	✅
Documentation Site	✅	❌	❌	✅
Auto-Update Checker	✅	❌	❌	❌
CI/CodeQL	✅	⚠	❌	✅
License	MIT	MIT	MIT	MIT

Standard Library Comparison (Automatic vs Manual)

Feature	logly.zig	std.log	Notes
Log Levels	✅ 10 levels (trace → fatal)	4 levels (debug, info, warn, err)	logly.zig has more granularity
Custom Levels	✅ Automatic	❌	Define your own levels
Colored Output	✅ Automatic	❌	Cross-platform ANSI colors
JSON Output	✅ Automatic	❌ Manual	Built-in JSON formatter
File Output	✅ Automatic	❌ Manual (stderr only)	Must implement manually for std.log
Async Logging	✅ Automatic	❌ Manual	Ring buffer with workers
Context Binding	✅ Automatic	❌ Manual	Persistent fields across logs
Formatted Logging	✅ Automatic templates	✅ Manual format strings	std.log uses basic printf-style
Thread Safety	✅ Automatic (advanced)	✅ Basic	logly.zig has lock-free options
Performance Tuning	✅ Automatic presets	❌ Manual	Production/development presets
File Rotation	✅ Automatic	❌ Manual	Time + size based rotation
Compression	✅ Automatic	❌ Manual	gzip/zlib/zstd support
Network Logging	✅ Automatic	❌ Manual	TCP/UDP sinks
Redaction	✅ Automatic	❌ Manual	PII masking built-in
Metrics	✅ Automatic	❌ Manual	Built-in counters and stats
Distributed Tracing	✅ Automatic	❌ Manual	Trace/span/correlation IDs
Rules System	✅ Automatic triggers	❌	Template-based diagnostic messages

Automatic vs Manual

• Automatic: Feature works out-of-the-box with configuration
• Manual: Feature requires custom implementation by the developer
• std.log provides raw performance but requires manual implementation for most features

Performance Comparison

Scenario	logly.zig	nexlog	log.zig	std.log
Simple text logging (ops/sec)	117,334	41,297	~120,000	~150,000( avg-based on hardware)
Colored logging (ops/sec)	116,864	~38,000	~105,000	N/A
Formatted logging (ops/sec)	37,341	~30,000	~20,000	N/A (manual)
JSON compact (ops/sec)	53,149	26,790	~35,000	N/A
JSON formatted (ops/sec)	30,426	~22,000	~25,000	N/A
JSON pretty (ops/sec)	15,963	~12,000	~18,000	N/A
Async high-throughput (ops/sec)	36,483,035	~180,000	N/A	N/A
Multi-threaded (4 threads, ops/sec)	51,211	~22,000	~18,000	N/A (based on implementation)
Multi-threaded JSON (4 threads, ops/sec)	37,412	~14,000	~12,000	N/A
Avg latency – minimal config (ns)	8,758	~24,000	~8,000	N/A (based on implementation)
Avg latency – JSON compact (ns)	18,815	~37,000	~28,000	N/A
Avg latency – production preset (ns)	28,278	~45,000	~35,000	N/A
Max observed throughput (ops/sec)	36.48M	~0.18M	~0.12M	N/A (based on implementation)
Avg baseline latency (ns)	~939	~25,000	~8,500	N/A (based on implementation)

Performance Note

• std.log has the lowest raw latency (~5,000 ns) because it's minimal and outputs to stderr only
• logly.zig trades slightly higher latency for automatic features (colors, JSON, rotation, etc.)
• All metrics vary based on system, OS, Zig version, hardware, and build configuration
• N/A means the feature is not available or requires manual implementation

Rules System (v0.1.0+)

Logly.zig includes a unique Rules System that provides compiler-style guided diagnostics:

// Define a rule that triggers on error logs containing "Database"
try rules.add(.{
    .id = 1,
    .level_match = .{ .exact = .err },
    .message_contains = "Database",
    .messages = &[_]logly.Rules.RuleMessage{
        .cause("Connection pool exhausted"),
        .fix("Increase max_connections in config"),
        .docs("DB Guide", "https://docs.example.com/db"),
    },
});

// When logging:
try logger.err("Database connection timeout", @src());

// Output:
// [ERROR] Database connection timeout
//     >> [ERROR] Connection pool exhausted
//     >> [FIX] Increase max_connections in config
//     >> [DOC] DB Guide (https://docs.example.com/db)

This feature is not available in std.log, nexlog, or log.zig.

Links

Library	GitHub
logly.zig	github.com/muhammad-fiaz/logly.zig
nexlog	github.com/chrischtel/nexlog
log.zig	github.com/karlseguin/log.zig
std.log	Zig Standard Library

Why Choose Logly.zig?

Advantages

1. Feature Complete: Most comprehensive feature set among Zig logging libraries
2. Automatic Everything: Features work out-of-the-box vs manual implementation
3. High Performance: Optimized async logging with up to 36M ops/sec throughput
4. Enterprise Ready: Built-in redaction, metrics, distributed tracing
5. Rules System: Template-triggered diagnostic messages (unique feature)
6. Developer Friendly: Intuitive API with extensive documentation
7. Production Tested: Compression, rotation, and retention policies
8. Cross-Platform: Works on Linux, macOS, Windows, and bare-metal

When to Use std.log Instead

• Ultra-minimal latency is the only requirement (~5,000 ns vs ~8,758 ns)
• Simple applications with basic stderr logging needs
• When minimizing dependencies is critical (zero dependencies)
• Embedded systems with extreme memory constraints
• Quick prototyping without external dependencies
• You're willing to manually implement features like file output, rotation, JSON, etc.

Migrating from std.log

// Before (std.log) - Manual, basic
const std = @import("std");
std.log.info("Hello, {s}!", .{"world"});
std.log.err("Error occurred: {}", .{error_code});

// After (logly.zig) - Automatic features
const logly = @import("logly");
var logger = try logly.Logger.init(allocator, .{});
defer logger.deinit();

try logger.info("Hello, {s}!", .{"world"}, @src());
try logger.err("Error occurred: {}", .{error_code}, @src());

See Also

• Getting Started
• Installation
• Configuration
• Rules System