space4.dev · by Shreeji Softech
Developer tools that never upload your data
Format JSON, encode Base64, decode JWTs, convert Unix timestamps, validate OpenAPI — space4.dev runs 75+ utilities entirely in your browser. Free, no signup, private by design.
Start here
- Step 1
Pick a tool
Jump to a popular tool below, or search the catalog with ⌘K.
- Step 2
Paste your input
Drop in API payloads, tokens, or specs. Processing stays in your browser.
- Step 3
Copy the result
Beautify, decode, validate, or convert — then copy or download. No signup.
JSON
15 toolsFormat, validate, explore, and transform JSON data.
JSON Formatter
Beautify, minify, and validate JSON instantly in your browser.
JSON Viewer
Explore JSON as an interactive tree with search and expand controls.
JSON Validator
Validate JSON syntax instantly with clear error messages.
JSON Minifier
Minify JSON into a compact single-line payload.
JSON Prettifier
Pretty-print JSON with clean indentation for readability.
JSON Compare
Compare two JSON documents and highlight structural changes.
JSON Diff
Generate a line-by-line diff of two JSON documents.
JSON to YAML
Convert JSON into clean YAML instantly.
JSON to XML
Convert JSON data into XML markup.
JSON to CSV
Flatten JSON into CSV for spreadsheets and exports.
JSON to TypeScript
Generate TypeScript interfaces from JSON samples.
JSON to Java
Generate Java class stubs from JSON data.
JSON to C#
Generate C# classes from JSON samples.
JSON to PHP Array
Convert JSON into a PHP array literal.
Escape / Unescape JSON
Escape text into JSON strings or unescape JSON literals.
Encoding & Decoding
49 toolsEncode and decode Base64, URL, HTML, Unicode, JWT, binary, and more — entirely in your browser.
Base64
Base64 Encoder
Encode text to Base64 instantly in your browser.
Base64 Decoder
Decode Base64 strings back to readable text.
Base64 Image Decoder
Preview images from Base64 or Data URI strings.
Base64 Image Encoder
Convert images to Base64 for embedding in CSS or HTML.
Base64 URL Encoder
Encode text as URL-safe Base64 (Base64URL).
Base64 URL Decoder
Decode URL-safe Base64 (Base64URL) strings.
URL
URL Encoder
Percent-encode text for safe use in URLs.
URL Decoder
Decode percent-encoded URL strings.
URL Parser
Break a URL into protocol, host, path, query, and hash.
URL Query Parser
Parse query strings into a readable JSON object.
URL Builder
Build a full URL from JSON parts.
URL Query String Generator
Turn a JSON object into a query string.
HTML
Unicode
Unicode Encoder
Convert text to Unicode escape sequences.
Unicode Decoder
Decode \uXXXX and \u{…} escape sequences.
Unicode Escape
Escape text as Unicode code-point sequences.
Unicode Unescape
Unescape Unicode sequences to readable text.
ASCII ↔ Unicode Converter
Convert between plain text and Unicode escapes.
JWT
Text Encoding
UTF-8 Encoder
Encode text to UTF-8 byte values.
UTF-8 Decoder
Decode UTF-8 byte lists back to text.
UTF-16 Converter
Convert text to and from UTF-16 code units.
ASCII Converter
Convert text to ASCII / Unicode code points.
Binary Converter
Convert text to binary and back.
Hex Converter
Convert text to hexadecimal and back.
Octal Converter
Convert text to octal byte values and back.
Binary & Hex
Text → Binary
Convert plain text into binary bytes.
Binary → Text
Convert binary bytes back into text.
Text → Hex
Convert plain text into hexadecimal.
Hex → Text
Convert hexadecimal into text.
Binary ↔ Hex
Convert between binary and hexadecimal.
Decimal ↔ Binary
Convert decimal numbers to binary and back.
Decimal ↔ Hex
Convert decimal numbers to hex and back.
Data URI
MIME
Date & Time
5 toolsConvert timestamps, compare dates, shift time zones and work with cron expressions.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and back.
Date Difference Calculator
Calculate the exact difference between two dates.
Time Zone Converter
Convert a date and time between world time zones.
Cron Expression Parser
Explain cron schedules and preview upcoming run times.
Cron Expression Generator
Build and validate 5-field cron expressions visually.
OpenAPI
6 toolsView, validate, format, convert, and diff OpenAPI / Swagger specs — entirely in your browser.
OpenAPI
OpenAPI Viewer
Explore OpenAPI / Swagger specs — paths, operations, schemas, and security.
OpenAPI Validator
Validate OpenAPI 2.0, 3.0, and 3.1 documents with clear errors and warnings.
OpenAPI Formatter
Pretty-print or minify OpenAPI JSON and YAML with indent and key sorting.
JSON to OpenAPI
Infer schemas from sample JSON and generate an OpenAPI 3.1 document.
OpenAPI Example Generator
Generate realistic request and response examples from an OpenAPI spec.
OpenAPI Diff
Compare two OpenAPI specs for added, removed, and breaking changes.
Free online developer tools — private by default
space4.dev is a practical toolkit for everyday engineering work: beautify and validate JSON, encode or decode Base64 and URLs, inspect JWTs, convert Unix timestamps, parse cron, and explore OpenAPI specs. Every utility is designed to run in your browser so API keys, customer payloads, and internal documents are not uploaded for conversion.
Unlike generic “1001 tools” directories, we focus on workflows developers actually repeat — formatting payloads before a PR, checking a token’s claims, or linting an OpenAPI file before CI. Browse 75+ published tools across JSON, Encoding & Decoding, Date & Time, OpenAPI.
Built and maintained by Shreeji Softech. Questions or tool requests? Email contact.shreejisoftech@gmail.com.
Who it’s for
Backend and frontend engineers, QA, technical writers, and students who need trustworthy utilities without installing desktop apps.
What makes us different
Privacy is a product constraint: tools are static pages with client-side logic. No account is required to format, decode, or validate.
How to start
Open a tool, paste input, copy the result. Use ⌘K to search the catalog, or jump into a category hub.
Popular free tools
- JSON Formatter — Beautify, minify, and validate JSON instantly in your browser.
- JSON Viewer — Explore JSON as an interactive tree with search and expand controls.
- JSON Validator — Validate JSON syntax instantly with clear error messages.
- JSON Minifier — Minify JSON into a compact single-line payload.
- JSON Prettifier — Pretty-print JSON with clean indentation for readability.
- JSON Compare — Compare two JSON documents and highlight structural changes.
- JSON Diff — Generate a line-by-line diff of two JSON documents.
- JSON to YAML — Convert JSON into clean YAML instantly.
- JSON to XML — Convert JSON data into XML markup.
- JSON to CSV — Flatten JSON into CSV for spreadsheets and exports.
- JSON to TypeScript — Generate TypeScript interfaces from JSON samples.
- JSON to Java — Generate Java class stubs from JSON data.
- JSON to C# — Generate C# classes from JSON samples.
- JSON to PHP Array — Convert JSON into a PHP array literal.
- Escape / Unescape JSON — Escape text into JSON strings or unescape JSON literals.
- Base64 Encoder — Encode text to Base64 instantly in your browser.
- Base64 Decoder — Decode Base64 strings back to readable text.
- Base64 Image Decoder — Preview images from Base64 or Data URI strings.
Why developers choose space4.dev
- 100% client-side processing for privacy-sensitive work
- No signup walls, installers, or paywalled basics
- Guides and FAQs on major tools — not empty shells
- Related tools grouped by category for faster workflows
- Works on desktop and mobile browsers
Editorial note
Each featured tool page includes original how-to guidance and FAQs written for real debugging scenarios. Prefer canonical URLs like https://space4.dev/json-formatter.
Browse by category: JSON, Encoding & Decoding, Date & Time, OpenAPI. Or visit all categories and learn more about space4.dev.