Handle JSON, JWT and cURL while debugging APIs
Developer Collection
Online Developer Tools Launchpad
API debugging, data conversion, regex testing, Git reference, Markdown, SQL, Docker, Cron and SEO meta tools.
A daily developer toolbox that brings together JSON utilities, data conversion, cURL to code, JWT parsing, regex testing, Git cheatsheets, Markdown preview, SQL formatting, Docker Compose conversion, Cron expressions, HTTP status codes and meta tag generation.
16Curated tools
3Workflows
3FAQ answers
Built for these intents
Preview Markdown, format SQL or look up Git commands while writing docs
Test regex, keyboard events and device details for frontend debugging
Generate SEO, OG and Twitter Card tags before publishing pages
Tools in this hub
JSON Formatter
Beautify, minify and validate JSON data with syntax error detection. Supports JSON formatter, JSON beautify. Bidirectional, instant preview, one-click copy. Free at oltool.net.
Data Format Converter
Convert between JSON, YAML, TOML, XML and CSV in one place with a single paste and instant preview. Supports data format converter, JSON YAML TOML XML CSV. Runs locally — no data uploaded. Free at oltool.net.
cURL to Code
Convert cURL commands to Python, JavaScript, PHP, Go, Java code with auth and JSON body. Supports cURL, curl converter. Built for developers, works offline. Free at oltool.net.
JWT Parser
Decode and inspect JWT tokens (header, payload, expiry) with signature check. Supports JWT, JWT decode. Built for developers, no signup, works offline. Free at oltool.net.
Regex Tester
Test JavaScript regular expressions with flags (g/i/m/s/u) and capture groups. Supports regex, regex tester. Real-time browser processing, paste-and-go. Free at oltool.net.
Git Cheatsheet
Quick reference for common git commands (init, commit, branch, merge, rebase). Supports git, git cheatsheet. Real-time browser processing, paste-and-go. Free at oltool.net.
Markdown Preview
Render Markdown to HTML in real time with markdown-it, GFM, code blocks and tables. Supports Markdown, Markdown preview. Real-time browser processing. Free at oltool.net.
SQL Formatter
Format and indent SQL queries with regex-based prettifier for SELECT/INSERT/UPDATE. Supports SQL formatter, SQL prettify. Bidirectional, one-click copy. Free at oltool.net.
docker run to compose
Convert a docker run command to docker-compose.yml with ports, volumes, env vars. Supports docker, docker-compose. Bidirectional, one-click copy. Free at oltool.net.
Crontab Generator
Build cron expressions with visual editor and preview their human meaning. Supports cron, crontab. Built for developers, no signup, works offline. Free at oltool.net.
HTTP Status Codes
Reference for HTTP status codes (1xx-5xx) with meanings and examples. Supports HTTP status, HTTP code. Built for developers, no signup, works offline. Free at oltool.net.
Open Graph Meta Generator
Generate meta tags for SEO, Open Graph and Twitter cards with live preview. Supports Open Graph, meta tags. Built for developers, no signup, works offline. Free at oltool.net.
Open Graph Meta Generator
Build Open Graph and Twitter Card meta tags with live preview and social sharing. Supports Open Graph, OG meta. Built for developers, no signup, works offline. Free at oltool.net.
Keycode Info
Show the key code and event details for any keypress (keyCode, key, code, location). Supports keycode, keyboard code. Built for developers, works offline. Free at oltool.net.
Device Information
Display browser, OS, screen, GPU and runtime info with viewport and pixel ratio. Supports device info, browser info. Built for developers, works offline. Free at oltool.net.
HTML WYSIWYG Editor
Visual rich-text editor that outputs clean HTML with bold, italic, lists and links. Supports WYSIWYG, HTML editor. Real-time browser processing, paste-and-go. Free at oltool.net.
Suggested workflows
API development
Format JSON, inspect JWT tokens and convert cURL commands into application code.
Engineering config
Convert data formats, generate docker-compose files and check Cron expressions.
Frontend release
Generate meta tags, prepare Open Graph previews and inspect device details for compatibility.
How this developer hub helps
Collects daily micro-tasks
Developers repeatedly format, convert, validate, reference and generate snippets; this page keeps common tasks together.
Avoids temporary dependencies
Many one-off tasks do not justify installing a CLI or opening a large IDE.
Easy to share with teams
Add the hub link to internal docs so teammates use the same tools for common debugging work.
Developer tools FAQ
Do these tools require sign-in?
No. OLTool utilities are free to use and most features work immediately after loading.
Are they suitable for internal team usage?
Yes. Data is processed locally in the browser, which is helpful for common debugging snippets.
How is this different from the homepage?
The homepage lists everything; this developer hub highlights the most common programming workflow tools.