Developer Tools

Format, encode and decode without leaving the browser.

JSON Formatter
Format, minify, and validate JSON in your browser — pretty-print or compress with pinpoint error locations.
Subnet Calculator
Enter an IP and CIDR prefix or subnet mask to instantly get network, broadcast, host range, and mask details.
Diff Checker
Compare two texts line by line and see exactly what was added, removed, or unchanged — in your browser.
UUID Generator
Generate cryptographically random RFC 4122 v4 UUIDs in bulk — copy one or all, in your browser.
Unix Timestamp Converter
Convert Unix timestamps to human dates (UTC, local, ISO 8601) and back — instantly, in your browser.
JSON Validator
Check if JSON is valid, pinpoint syntax errors by line and column, and see a structure diagnostic, in-browser.
Regex Tester
Test JavaScript regex live — see every match, capture group, and named group highlighted as you type.
XML Formatter
Beautify or minify XML instantly in your browser — no upload.
JWT Decoder
Decode a compact JWT header and payload locally, with a clear unverified warning.
Excel Keyboard Shortcuts
Search practical Excel shortcuts by action, platform, and category, then copy the exact keys you need.
ASCII Table
Look up every standard 7-bit ASCII code with exact decimal, hexadecimal, octal, and binary values.
HTTP Status Codes
Find registered HTTP response codes by number, phrase, response class, meaning, or RFC reference.
JSON To CSV
Convert a JSON object array into RFC 4180-style CSV locally with default spreadsheet formula protection.
Regex Cheat Sheet
Find and copy JavaScript RegExp tokens without mixing syntax from another regular-expression dialect.
CSS Grid Generator
Build a bounded CSS Grid with explicit columns, rows, gap, and item alignment, preview it live, and copy standards-based declarations.
Flexbox Generator
Configure five core Flexbox controls, inspect a fixed multi-item preview, and copy deterministic CSS without arbitrary style input.
PX to REM Converter
Convert CSS lengths between pixels and rem units with a custom root font size and copy-ready output.
CSV To JSON
Parse a bounded RFC 4180-style comma file locally and export string-preserving JSON without losing quoted commas, quotes, or line endings.
Code to Image Generator
Turn complete code text into a clean light or dark PNG locally, without uploading or executing it.
HTML Cleaner
Normalize an HTML fragment through the browser parser and optionally remove comment nodes without previewing or executing the result.
JSON Minifier
Turn strict JSON into a compact JSON.parse and JSON.stringify result while explicitly rejecting duplicate keys and unsafe numeric rewrites.
Cookie to JSON Converter
Convert a strict Cookie request header to a JSON string map and back locally without decoding or silently overwriting values.
Directory Tree Generator
Turn a strict list of relative file paths into a deterministic, copy-ready directory tree without uploading project names or structure.
Dummy File Generator
Create an exactly sized zero-filled, secure-random, or repeated-text file locally for upload, storage, and transfer testing.
BOM Remover
Remove exactly one leading U+FEFF from pasted decoded text locally while preserving every internal, trailing, or second leading occurrence.
Chmod Calculator
Convert Unix permission bits between strict octal and complete rwx notation, including setuid, setgid, and sticky states.
URL Parser
Break an absolute HTTP or HTTPS URL into normalized, credential-safe components and ordered query parameters locally.
Online HTML Editor
Edit HTML and CSS side by side and render a deliberately restricted local preview without running scripts.
JavaScript Playground
Run short JavaScript snippets in a time-limited worker inside a unique-origin, network-blocked sandbox.
XML to JSON Converter
Convert bounded, well-formed XML into readable JSON locally with attributes, text, namespaces, and repeated elements preserved.
MAC Address Generator
Generate 1–20 cryptographically random, locally administered unicast 48-bit MAC addresses for safe test data.
Microsoft Word Keyboard Shortcuts
Search 20 common Microsoft Word keyboard shortcuts with separate Windows and Mac mappings.
Cron Expression Generator
Build a standard five-field cron expression from a readable schedule without memorizing field order.
Public NTP Server List
Compare official public NTP hostnames and copy ready-to-review ntpd configuration lines.
VS Code Keyboard Shortcuts
Search 20 common default VS Code keyboard shortcuts with separate Windows, Linux, and macOS mappings.
IPv6 Subnet Calculator
Calculate an IPv6 network prefix, canonical address, first and last numeric address, host bits, and exact range size locally.
JSON To XML
Convert JSON into escaped, typed XML with a documented deterministic mapping, custom root name, and no uploads.
CSS Box Shadow Generator
Design one standards-shaped CSS box shadow visually and copy a deterministic declaration without external code generation.
PowerPoint Keyboard Shortcuts
Search a verified compact set of Microsoft PowerPoint desktop shortcuts without guessing Windows-to-Mac substitutions.
Badge Generator
Build a Shields.io badge URL, Markdown snippet, and HTML image tag without memorizing path escapes or query parameters.
Clipboard Viewer
Inspect clipboard text locally, reveal invisible whitespace, and measure characters, code points, UTF-8 bytes, lines, words, and JSON validity.
Cron Parser
Validate a classic five-field cron expression, explain its selected fields, and calculate the next five matching times.
CSS Border Radius Generator
Shape four CSS corners visually and copy the shortest correct border-radius declaration.
CSS Button Generator
Design a reusable CSS button with coordinated colors, spacing, border, typography, radius, and shadow.
CSS Clip Path Generator
Create and edit percentage-based CSS polygon clips with live presets and validated coordinate pairs.
CSS Glassmorphism Generator
Tune a transparent glass panel with validated blur, alpha, border, and radius values, then copy production-ready CSS.
CSS Gradient Generator
Build a three-color linear gradient with exact angle and ordered percentage stops, then copy the validated CSS declaration.
CSS Loader Generator
Generate a lightweight CSS ring spinner with bounded size, width, colors, and duration plus accessible implementation guidance.
CSS Neumorphism Generator
Create a balanced soft-interface surface with validated color contrast, paired shadows, blur, distance, and corner radius, then copy the exact CSS.
CSS Speech Bubble Generator
Build a CSS speech bubble with validated colors, radius, tail size, and four tail directions, then copy the complete pseudo-element rule.
CSS Stripes Generator
Generate a deterministic repeating stripe background with validated angle, two colors, stripe width, and gap width, then copy one CSS declaration.
CSS Text Shadow Generator
Tune a single CSS text shadow with exact offsets, blur, colors, and a real preview, then copy the validated declaration.
Camel Case to Snake Case Converter
Split identifiers and phrases across acronym, camel-case, separator, and digit boundaries, then copy six deterministic naming styles.
Excel Formulas Cheat Sheet
Search twelve verified everyday Excel functions by name, category, syntax, or purpose and copy the vendor-style argument signature.
File Signatures (Magic Bytes) List
Search twelve source-checked file signatures by format, extension, hexadecimal prefix, or note and copy the exact offset-zero bytes.
Git Cheat Sheet
Search twelve source-checked Git commands by workflow or purpose, copy a safe template, and review the placeholder and history warnings.
Hello World in Different Programming Languages
Search twelve source-checked Hello World examples by language, runtime, filename, or code and copy a conventional command-line entry point.
HTML to JavaScript Converter
Turn raw HTML into a valid const assignment using double quotes, single quotes, or a template literal while escaping every delimiter and control character locally.
IP to Decimal Converter
Convert strict dotted-decimal IPv4 addresses to exact unsigned 32-bit integers and reverse them without rounding, leading-zero ambiguity, or network requests.
IPv4 to IPv6 Converter
Convert a strict IPv4 address into RFC 4291 IPv4-mapped IPv6 mixed, compressed hexadecimal, and fully expanded forms with exact bit placement.
JavaScript Key Code Finder
Press a real key and inspect its layout-aware key value, physical code, location, modifiers, repeat and composition flags, plus the deprecated keyCode.
Linux Commands Cheat Sheet
Search thirteen source-checked GNU/Linux file, text, location, and disk commands and copy conservative templates without destructive flags.
Mesh Gradient Generator
Layer four standards-based radial gradients over a base color, tune their colors and fade spread, preview the result, and copy exact CSS locally.
MIME Type Lookup
Search 24 source-checked media types by extension, format, or MIME string, then copy the exact registered value.
Nano ID Generator
Generate up to 100 cryptographically random Nano ID-compatible strings with a validated length from 1 to 128 characters.
Photoshop Keyboard Shortcuts
Search 16 source-checked Photoshop desktop shortcuts, switch between Windows and macOS, and copy the exact default keys.
Query String Parser
Convert query strings to readable JSON and flat JSON objects back to encoded query strings while preserving repeated keys.
SVG to Base64 Converter
Encode complete Unicode SVG source as a UTF-8 Base64 data URL or decode that exact data URL back to text.
HTML Table to JSON Converter
Extract text from the first HTML table and convert rows into predictable JSON objects with safe header handling.
ANSI Color Codes Generator
Build and copy raw SGR escape sequences and search the standard 8 plus bright 8 terminal color codes.
Text to HTML Paragraphs Converter
Convert plain text blocks into escaped HTML paragraphs with an explicit choice for single line breaks.
ULID Generator
Generate monotonic ULID batches from cryptographic randomness and decode the embedded millisecond timestamp.
CSV to HTML Table Converter
Convert RFC 4180-style CSV into escaped, structured table markup with a safe React preview and exact clipboard output.
JSON to Zod Schema Converter
Infer a reviewable Zod schema from one JSON sample, including nested objects, arrays, unions, nullable values, and optional merged fields.
XPath Tester
Evaluate XPath 1.0 against detached XML and inspect node, string, number, or Boolean results without inserting matched markup.
JSON Schema Generator
Infer a Draft 2020-12 JSON Schema from sample structure with required presence, nullable values, arrays, mixed types, and explicit uncertainty.
JSON to Rust Struct Converter
Infer reviewable Serde Rust structs from JSON, including nested objects, vectors, optional fields, nulls, renames, and normalized identifier collisions.
Properties to JSON Converter
Parse Java load(Reader)-style properties into string-valued JSON with continuations, escapes, comments, and duplicate replacement handled explicitly.
JSON to HTML Table Converter
Turn strict JSON objects into an escaped, copy-ready HTML table with deterministic union columns and a safe text preview.
Quartz Cron Expression Generator
Build reviewable six- or seven-field Quartz cron expressions for intervals, weekdays, monthly rules, last days, and nth weekdays.
XML to CSV Converter
Convert repeated XML record elements to RFC-style CSV with attributes, repeated children, exact tag selection, and optional formula protection.
IEEE 754 Floating Point Converter
Encode decimal values to IEEE 754 binary32 or binary64 fields and decode exact bit or hexadecimal patterns back to browser numbers.
JSON Diff
Compare two strict JSON values structurally and receive deterministic added, removed, changed, and type-changed entries at JSON Pointer paths.
JWT Generator
Create a compact HS256 JWT from strict JSON claims with standards-based base64url encoding and browser-native HMAC-SHA-256.
Common Network Ports List
Search a curated table of common TCP and UDP ports by number, registered service, protocol, category, or practical description.
Create ZIP File Online
Put selected local files into one downloadable ZIP archive without uploading them.
Excel To CSV
Export one selected worksheet from a local .xlsx workbook as a formula-safe CSV download in your browser.
Excel to JSON Converter
Turn one selected worksheet from a local .xlsx file into a readable JSON download without uploading the workbook.
Excel Viewer Online
Open a local .xlsx worksheet in a bounded browser preview without uploading the workbook or executing spreadsheet formulas.
CSV to Excel Converter
Turn a local CSV table into a downloadable .xlsx workbook without uploading the file or running spreadsheet formulas.
Excel to HTML Table Converter
Convert one local .xlsx worksheet into an escaped HTML table snippet without uploading the workbook or executing spreadsheet content.
JSON to Excel Converter
Convert a JSON array of objects into a local .xlsx workbook while preserving first-seen field order and never uploading the data.
Excel Column Extractor
Extract one selected column from a local .xlsx worksheet as a formula-safe CSV download without uploading the workbook.
Excel Hyperlink Extractor
List safe external hyperlinks stored in a local .xlsx workbook without uploading the file, following a URL, or running spreadsheet content.
Split Excel Sheets
Split every worksheet from a local .xlsx workbook into separately named data-only .xlsx files inside one ZIP download.
Merge Excel Files
Combine the stored values from 2 to 10 local .xlsx workbooks into one bounded data-only Excel download without uploading any file.

About these tools

Every tool in developer tools runs locally in your browser: files are processed on your device and never uploaded to a server. That makes them fast, private and safe to use with sensitive documents, at work or at home.