Free online developer tools

Quartz Cron Generator

Build and validate Quartz cron expressions for Java and Spring Boot.

Cron Expression Translator

Translate cron to plain English, validate syntax, and preview next run times.

Snowflake ID Decoder

Decode Twitter, Discord, Instagram, and LinkedIn Snowflake IDs into timestamps and components.

ULID Generator and Decoder

Generate sortable ULIDs and decode timestamps from existing IDs.

Protobuf Decoder

Decode Protocol Buffers wire format from hex or base64 without a .proto schema.

JWT Decoder and Inspector

Decode JWT tokens in your browser. View the header, payload, claims, and expiration.

Protobuf Decoder

Decode Protocol Buffers wire format from hex or base64 without a .proto schema.

SSL/TLS Certificate Decoder

Parse X.509 certificates. See subject, issuer, validity, SANs, and fingerprints.

LLM Token Counter

Count tokens for GPT-4, Claude, Llama, Gemini, and Mistral. Estimate prompt cost.

UUID Generator and Decoder

Generate UUID v4 and v7. Decode existing UUIDs and extract timestamps.

ULID Generator and Decoder

Generate sortable ULIDs and decode timestamps from existing IDs.

NanoID Generator

Generate compact, URL-safe unique IDs. Custom size, alphabet, and bulk generate.

KSUID Generator and Decoder

Generate time-sortable KSUIDs and decode timestamps from existing IDs.

Snowflake ID Decoder

Decode Twitter, Discord, Instagram, and LinkedIn Snowflake IDs into timestamps and components.

Epoch Timestamp Converter

Convert Unix epoch seconds or milliseconds to readable dates and back.

Cron Expression Translator

Translate cron to plain English, validate syntax, and preview next run times.

Quartz Cron Generator

Build and validate Quartz cron expressions for Java and Spring Boot.

JSON Validator and Formatter

Validate JSON with line and column errors. Format output in one click.

YAML Validator and Formatter

Validate YAML for Kubernetes, Docker Compose, and CI configs.

TOML Validator and Formatter

Validate TOML for Cargo.toml, pyproject.toml, and Hugo configs.

CSV to JSON Converter

Convert CSV to JSON with headers, delimiters, copy, and download.

XPath Tester

Test XPath expressions against XML or HTML with live match results.

HMAC Generator and Verifier

Generate and verify HMAC-SHA256 and other HMAC signatures in your browser.

Hash Generator

Create MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text or a file.

MD5 Hash Generator

Generate an MD5 hash instantly from text or a file. Hex or Base64 output.

SQL Formatter and Beautifier

Format SQL for MySQL, PostgreSQL, SQL Server, and Oracle.

HTML Beautifier

Pretty print and minify HTML in your browser. Indent tags or collapse whitespace.

SVG Viewer

Preview SVG markup or a local .svg file. Inspect viewBox, copy a data URI, download.

Base64 Encoder and Decoder

Encode text to Base64 or decode Base64 strings with UTF-8 support.

Base64 to PDF Converter

Convert Base64 to PDF with preview and download, or encode PDF to Base64.

URL Encoder and Decoder

Percent-encode strings for URLs or decode URL-encoded text.

RGB to Hex Converter

Convert RGB and RGBA channel values to CSS hex colors.

Hex to RGB Converter

Convert #RRGGBB and shorthand hex colors to rgb() and rgba().

Curl Converter

Convert curl commands to Python, Go, Java, Axios, PHP, C#, and more.

HAR File Viewer

Open HAR exports from Chrome or Firefox. Inspect requests, headers, and timing.

User Agent Parser

Parse User-Agent strings for browser, OS, device, and bot detection.

Subnet Calculator

Calculate IPv4 and IPv6 subnets. Get network, broadcast, mask, and host ranges.

Chmod Calculator

Convert between octal and symbolic Linux file permissions.

SLA and Uptime Calculator

Calculate allowed downtime for 99.9%, 99.99%, and other SLA targets.

Regex Tester and Debugger

Test regular expressions with live highlighting and capture groups.

Text Diff Checker

Compare two text or code blocks with side by side and inline diff views.

Password Generator

Generate strong random passwords and memorable passphrases. Dedicated 8, 12, 16, 24, and 32 character password generators.

Fake Data Generator

Generate realistic mock, dummy, and test data. Export as JSON, CSV, or SQL INSERT statements.

QR Code Generator

Create custom QR codes for URLs, text, email, phone, and WiFi. Download as PNG or SVG.

Lorem Ipsum Generator

Generate placeholder paragraphs, sentences, or words for layouts and mockups.

CBOR Decoder

Decode RFC 8949 CBOR payloads to JSON from hex, base64, or a .cbor file.

AWS EventBridge Cron Generator

Generate and validate AWS EventBridge cron and rate expressions for Rules, Scheduler, and Lambda.