A developer'sonline toolbox
Nginx reverse proxy, Docker Compose, cron, regex… common configs and commands, generated from a form and ready to copy. Everything runs locally in your browser — no signup, nothing uploaded.
Less syntax to memorize, fewer docs to search — fill in the common configs and commands, then copy and go.
Find tools by development stage
From writing code to going live, the tools for each step are marked along the flow. Not sure what to look for? Just follow the flow.
- 1
Design / Assets
Colors, icons, images, favicons and other frontend assets.
- 2
Coding / Playground
Write code, try libraries online, write docs.
- 3
Data / Text
Format, convert, encode/decode, compare text.
- 4
API / Debug
Call APIs, decode tokens, look up various info.
- 5
Build / Package
Versions, dependencies, packaging apps into services.
- 6
- 7
- 8
Publish / SEO
Share cards, SEO checks, QR codes.
More general-purpose tools that span stages (by category, shipping continuously):
Color Tools
Image Tools
Encoding
All tools
37 tools · browse by categoryConfig Generators 3
Cron Expression Generator
Build crontab visually, get a plain-English explanation, and preview upcoming run times.
⑥ Scheduling & Ops
Nginx Reverse Proxy Config Generator
Generate a server block from a form, switch to Caddy in one click, with HTTPS / WebSocket support.
⑥ Deploy
Docker Compose Template Generator
Pick services (nginx/postgres/redis…) to assemble a compose file, ready to copy.
⑤ Build / Package
Dev Utilities 11
Tech Stack Picker
Combine frontend/backend/database/config, understand each technology and its 2026 trend, and see what kind of project the stack suits.
① Planning / Selection
Unix Timestamp Converter
Convert between Unix timestamps and dates, auto-detect seconds/milliseconds, local and UTC.
④ API / Debug
UUID Generator
Generate UUID v4 in bulk, with uppercase and hyphen-free options, copy in one click.
④ API / Debug
JWT Decoder
Decode a JWT header and payload, with expiry/issued times shown automatically.
④ API / Debug
Password Generator
Generate strong random passwords with adjustable length and character sets, from a secure source.
④ API / Debug
Hash Generator
Compute SHA-1 / SHA-256 / SHA-384 / SHA-512 hashes of text.
④ API / Debug
Timezone Converter
Convert one time across multiple world timezones, with daylight saving handled automatically.
④ API / Debug
Directory Tree Generator
Turn an indented list into an ASCII directory tree with ├── └── connectors.
⑤ Build / Package
User-Agent Parser
Parse a User-Agent string to identify the browser, OS, and device type.
④ API / Debug
IP Address Lookup
Look up your public IP along with its location, ISP, and more.
④ API / Debug
Semver Version Tool
Validate semantic versions, test range satisfaction, and parse and compare version numbers.
⑤ Build / Package
Text Processing 9
Regex Tester
Live match highlighting, group explanations, built-in templates — paste and test instantly.
③ Data / Text
Base64 Encode / Decode
Convert text to and from Base64 with full UTF-8 support, processed locally in your browser.
③ Data / Text
URL Encode / Decode
Percent-encode and decode URL parameters, with support for non-ASCII and special characters.
③ Data / Text
JSON Formatter / Validator
Format, minify and validate JSON, sort keys, with precise error location.
③ Data / Text
Text Diff
Compare two texts line by line, highlighting additions, deletions, and changes, with stats.
③ Data / Text
Table Converter
Convert tables between CSV / JSON / Markdown / YAML / HTML in any direction, ready to copy.
③ Data / Text
HTML Entity Encode / Decode
Convert between characters and HTML entities (& ' etc.).
③ Data / Text
Unicode / Encoding Inspector
Inspect the Unicode code points and UTF-8 / UTF-16 encoding of text.
③ Data / Text
ASCII Table
A searchable ASCII reference table: decimal / hex / character.
③ Data / Text
Design Assets 9
CSS Gradient Generator
Adjust colors and angle visually, preview live, and generate CSS gradient code.
① Design / Assets
Color Converter
Convert between HEX / RGB / HSL, preview swatches, and generate a tint/shade scale.
① Design / Assets
Image Compressor
Compress JPG / PNG / WebP locally with adjustable quality and size — nothing uploaded.
① Design / Assets
QR Code Generator
Turn text / links into a QR code with adjustable size and error correction, download as PNG.
⑧ Publish / SEO
Favicon Generator
Upload an image to generate multi-size PNG icons, with the HTML reference code.
① Design / Assets
SVG Minifier
Strip comments and redundant whitespace to shrink SVGs, showing before/after size.
① Design / Assets
Color Contrast Checker
Compute the contrast ratio of two colors and judge readability against WCAG (AA/AAA).
① Design / Assets
Color Blindness Simulator
Simulate how colors appear under red-green and other color-vision deficiencies.
① Design / Assets
Image to Base64 / DataURL
Turn an image into a Base64 DataURL to embed directly in CSS/HTML.
① Design / Assets
Code & Docs 3
Markdown Table Generator
Fill a table visually, set column alignment, and get clean Markdown table code in real time.
② Coding / Playground
HTML to Markdown
Convert HTML into Markdown, preserving headings, lists, links, code, and more.
② Coding / Playground
Code Playground (HTML/CSS/JS)
Write HTML/CSS/JS online with a live sandbox preview on the right.
② Coding / Playground