Free Online Developer Tools
for Everyday Tasks
The only place to instantly check if your Telegram & WhatsApp group links still work — plus PDF, image, formatters, and dev tools, all free in your browser.
Social Media & Link Verifiers3
PDF & Document Tools2
Image Editors & Converters9
Image Compressor
Compress image files online for free. Reduce JPG, PNG, and WebP sizes with lossless and lossy optimization, live curtain slider, and 100% browser privacy.
Image Converter
Convert between JPG, PNG, WebP, BMP, and ICO formats in seconds offline in your browser with real-time visual comparison and custom background fill.
SVG to PNG Converter
Rasterize vector SVG files to PNG format with custom resolutions, high-DPI scaling (1x-8x), color tinting, batch ZIP packaging, and transparent or solid backgrounds.
SVG Optimizer
Clean, format, and minify vector SVG markup offline with batch ZIP packaging, React JSX / Vue exports, and visual comparison.
Image Cropper
Crop PNG, JPG, and WebP images to custom dimensions or social aspect ratios (1:1 avatar, 16:9 widescreen, 4:5 portrait, 9:16 story).
Favicon Generator
Create multi-size favicon packages and authentic .ico files from images, text, or emojis. 100% private in-browser tool with iOS, Android & PWA ZIP export.
Hue Shift Generator
Shift image and color hue values online with real-time preview, before/after visual curtain splitter, and HSL color palette extraction.
Data & JSON Formatters8
JSON Formatter & Validator
Free JSON formatter & validator: beautify, validate, auto-repair, and query JSONPath 100% locally in your browser. Fast, private, with zero server uploads.
Stringify JSON Online
Free tool to stringify JSON online: escape JSON into string literals or unescape stringified payloads back to JSON. 100% private in-browser.
Country Name Generator
Generate real world countries with ISO codes, capitals, currencies, flags, and dial codes, or create fictional fantasy nation names.
CSV ↔ JSON Converter
Free online CSV to JSON converter: transform CSV, TSV, and tabular data into JSON arrays or objects instantly. 100% client-side with zero server uploads.
SQL Formatter & Beautifier
Free SQL formatter: beautify, align, and minify SQL queries across PostgreSQL, MySQL, SQLite, and T-SQL. 100% private client-side engine with zero server logs.
XML Formatter & Beautifier
Format, validate, and minify XML markup with DevToys-style smart clipboard auto-detection, DOM AST tree inspection, and 7-format quick export.
Developer & Code Utilities16
HTML5 Validator
Validate HTML5 markup online for free. Check W3C living standards, WCAG 2.1 accessibility, heading outline, and SEO tags with zero latency.
.htaccess File Generator
Generate Apache .htaccess configuration files for HTTPS, canonical redirects, caching, compression, and security hardening.
HMO License Checker
Check whether a UK rental property requires Mandatory HMO, Additional, Selective, or Section 257 licensing with room space and amenity compliance.
Temperature Checker
Convert and check temperatures across 8 scales (Celsius, Fahrenheit, Kelvin, Rankine, Réaumur, Delisle, Newton, Rømer) with visual thermal gauge, delta intervals, specific heat, and weather comfort index.
UUID Generator
Free online UUID generator: create secure UUID v4, time-ordered v7, ULID, and NanoID identifiers offline with smart clipboard auto-detect and live inspector.
Regex Tester
Free regex tester: test regular expressions online with live match overlays, capturing groups, ReDoS risk detection, and code generation. 100% private.
Markdown Converter
Convert Markdown to HTML with live GFM visual rendering and syntax controls.
CSS, JS, HTML & JSON Code Minifier
Compress CSS, JavaScript, HTML, and JSON code to reduce file size by 20–60% with instant in-browser AST minification.
XML Schema Generator
Generate W3C XML Schema Definitions (XSD) from XML instances with Russian Doll, Venetian Blind, and Salami Slice designs.
Barcode Generator
Generate industrial 1D linear barcodes (Code 128, EAN-13, UPC-A, Code 39, ITF-14) with vector SVG, high-res PNG, bulk ZIP export, and printable label sheets.
Domain IP Converter
Convert domain names to IP addresses or perform reverse DNS lookups. Supports bulk conversion and IPv4/IPv6.
IP Search & Lookup
Search and lookup detailed IP address geolocation, network ISP, ASN, hostname, and security information.
Domain Extractor
Extract root domains, hostnames, subdomains, or full URLs from unstructured text, HTML, or server logs.
Email Extractor
Extract, deduplicate, filter, and normalize email addresses from text, HTML, logs, or CSV files.
Security, Hashes & Cryptography4
Hash Generator
Free online hash generator: compute MD5, SHA-1, SHA-256, SHA-512 digests instantly. 100% client-side with zero server uploads and file checksum verification.
JWT Decoder & Verifier
Decode, verify HMAC signatures, inspect claims, diagnose expiration, and craft JSON Web Tokens (RFC 7519) with 100% offline client-side security.
Encoders & Decoders6
Base64 Encoder & Decoder
Fast, private client-side Base64 encoder and decoder. Supports RFC 4648 URL-safe mode, MIME 76 line wrapping, PEM 64 chunks, RFC 4180 CSV matrix, hex dump, file upload/download, and DevToys smart clipboard detection.
URL Encoder & Decoder
Free online URL encoder decoder: percent-encode or decode URLs across 5 RFC-3986 modes with zero server uploads.
Binary Hex Converter
Convert binary to hexadecimal, decimal, and text 100% locally with 4-bit nibble breakdowns and bitwise logic.
Hexadecimal to Decimal Converter
Convert numbers between Hexadecimal (base-16) and Decimal (base-10) with step-by-step math proofs, binary nibbles, and IEEE-754 floats.
Text Analysis & String Tools20
Word Counter
Count words, characters, sentences, paragraphs, reading and speaking time, and readability scores instantly.
Text Case Converter
Convert text to UPPER, lower, Title, camelCase, snake_case, and more.
Color Converter
Convert between HEX, RGB, HSL, HSV, CMYK, OKLCH, HWB, and LAB color formats with live preview, WCAG contrast check, and color blindness tests.
Lorem Ipsum Generator
Free online lorem ipsum generator: create custom dummy text with 8 themes, 7 wrap formats, and live mockups. 100% private in-browser tool with instant copy.
Color Palette Generator
Generate harmonious color schemes with locks, extract colors from images, compute color harmonies, and export CSS or PNG offline.
Morse Code Translator
Translate sentences to Morse code dot-dashes, and decode back with audio tones.
String Splitter & Joiner
Free string splitter and joiner: split text by delimiter, chunk size, or regex into lists and JSON arrays. 100% private in-browser tool with zero uploads.
List Randomizer & Shuffler
Free online list randomizer and shuffler: shuffle text, draw raffle winners with live reveal, and split teams using unbiased Fisher-Yates CSPRNG. 100% private.
Reverse Text Converter
Reverse character sequences, flip word orders, invert lines, mirror Unicode glyphs, or generate upside-down text.
Diff Checker
Compare text and code online free with side-by-side or unified diff views.
Space Remover
Remove unwanted spaces, leading/trailing whitespace, duplicate spaces, blank lines, and tabs from text instantly.
Empty Row Remover
Clean blank lines, whitespace-only rows, duplicate entries, and messy line breaks with DevToys smart clipboard detection, live diff inspector, and multi-format exports.
Letter Counter
Count letters, characters, uppercase/lowercase, vowels/consonants, and analyze A-Z letter frequency distribution in real time.
Random Sentence Generator
Free random sentence generator: create creative writing prompts, typing practice drills, and UI placeholder copy across 10 curated themes.
Line Break Remover
Free online line break remover: remove unwanted line breaks, unwrap PDF and email text, and preserve paragraphs 100% privately in-browser with zero uploads.
Text Repeater
Free online text repeater: duplicate words, emojis, sentences, and lists up to 100,000 times with custom separators and numbering. 100% private in-browser.
ASCII Art Generator
Free online ASCII art generator: create retro FIGlet text banners, convert photos to ASCII art, and copy 50+ curated Kaomoji graphics 100% locally in-browser.
Text to ASCII Converter
Free online text to ASCII converter: convert text to ASCII decimal, hex, binary, and HTML entities or decode ASCII to text. 100% private in-browser matrix.
Math & Statistical Calculators11
Percentage Calculator
Free online percentage calculator: compute %, percentage increase/decrease, ratios, base totals, and fractions with step-by-step math. 100% private & offline.
Area Calculator
Calculate 2D shape areas, perimeters, unit conversions, and multi-room project surface totals offline.
FRAX Calculator
Calculate 10-year major osteoporotic fracture & hip fracture risk probability with clinical risk factors and BMD scoring.
Number List Generator
Generate sequential numbers, zero-padded IDs, hex/binary codes, Roman numerals, or randomized lists in your browser.
Number Sorter
Sort lists of numbers in ascending or descending order online. Supports decimals, negative values, delimiters, and stats.
Random Number Generator
Free random number generator: draw secure integers, decimals, Gaussian curves, and lottery picks. 100% private client-side CSPRNG with 1-click quick copy.
Raosoft Sample Size Calculator
Calculate required sample sizes, margin of error, Z-scores, and confidence intervals offline.
Coefficient Calculator
Calculate Pearson correlation (r), determination (R²), binomial combinations (nCk), CV %, and polynomial coefficients offline.
Simpson's Rule Calculator
Approximate definite integrals with Simpson's 1/3 rule, 3/8 rule, or discrete points with step-by-step tables and interactive graph.
Unit & Format Converters7
Length Unit Converter
Free online length unit converter: convert meters, feet, inches, miles, and km instantly. 100% private with interactive fractional ruler and multi-unit matrix.
Electrical Unit Converter
Free electrical unit converter: convert Voltage, Current, Resistance, Farads and Watts. Solve Ohm's Law privately in-browser with 1-click quick copy.
Power Unit Converter
Free online power unit converter: convert Watts, kW, horsepower (hp, PS), BTU/hr and TR instantly. 100% private in-browser tool with P=VI and torque solvers.
Weight & Mass Converter
Convert kilograms, pounds, ounces, grams, stone, troy ounces, carats, tolas, and atomic mass units with culinary density solvers and planetary gravity calculators.
Engineering Unit Converter
Convert pressure, power, force, torque, viscosity, flow rate, density, and thermal properties across 14 technical domains offline.
SEO & Web Optimization8
SEO Content Checker & SERP Simulator
Free online SEO content checker: audit readability, analyze keyword density, check heading hierarchy, and simulate Google SERP snippets 100% locally in-browser.
Meta Tag Preview
Preview and audit meta tags, Open Graph cards, and Google SERP snippets in real time. 100% private in-browser tool with Next.js, HTML & React tag generator.
Google Ads Headline Generator
Free Google Ads headline generator: create high-converting 30-character Responsive Search Ads headlines with live SERP preview, Ad Strength score, and CSV export.
Google Ads Description Generator
Free Google Ads description generator to create high-converting 90-character RSA descriptions, headlines, and live SERP previews.
Open Graph Generator
Generate, test, and preview Open Graph and Twitter Card meta tags for Facebook, Twitter/X, LinkedIn, Discord, and Slack.
URL Metadata Extractor
Extract, audit, and preview Open Graph, Twitter Cards, SEO tags, and JSON-LD schema from any URL or HTML code.
Time, Clocks & Epoch Tools7
Unix Epoch Converter
Convert epoch time to date and Unix timestamps 100% locally with multi-precision scale, batch logs, and SQL range bounds.
Age & Date Calculator
Calculate duration between dates, exact age, business working days, or add/subtract time offline.
Pomodoro Timer
Boost productivity with 25-minute focus sessions, customizable breaks, and task tracking.
Cron Expression Generator
Build, parse, and validate cron schedules visually with smart clipboard auto-detect, human-readable explanations, next 10 run previews, and multi-format script exports.
Countdown Timer
Precision online countdown timer with target date milestones, interval presets, Web Audio chimes, and ICS export.
Missing a tool? Suggest a new utility!
Let us know what online converters or checkers you need. We build them for free.
Developer Utility Categories
Over 96 utilities organized into 12 dedicated hubs. Every tool runs 100% in-browser with zero remote telemetry.
Social Media Tools
3 toolsFree online social media tools: verify Telegram & WhatsApp invite links anonymously, inspect group status, and create custom QR codes with zero login required.
PDF & Document Editors
2 toolsMerge multiple PDFs, slice page ranges, compress file sizes, convert formats, optimize SVGs, and crop graphics 100% locally in your browser with zero server uploads and lossless quality.
Image Editors & Optimizers
7 toolsFree online image tools: compress photos, convert formats (WebP, PNG, JPG), crop graphics, and pick colors 100% in-browser with zero uploads or tracking.
General Developer Tools
14 toolsFree online developer tools: format JSON, decode JWTs, generate UUIDs, test regex, and validate schemas 100% in-browser with zero server logging or tracking.
Math & Statistical Calculators
11 toolsCalculate percentages, geometric areas, sample sizes, correlation coefficients, definite integrals, and polyhedral dice probabilities 100% locally in your browser with zero calculation logging.
Security & Passwords
4 toolsGenerate high-entropy random passwords, compute cryptographic hashes (MD5, SHA-256, bcrypt), decode JWT tokens, and evaluate security credentials 100% offline in your browser.
Encoders & Decoders
6 toolsTranslate plain text into Base64 format, URL encoding schemes, HTML entities, binary nibbles, and hexadecimal radix formats safely 100% offline in your browser.
Data Formatters & Validators
8 toolsPrettify, validate, format, and convert JSON, YAML, CSV, SQL, and XML data structures bidirectionally 100% locally in your browser with zero server uploads and offline-first privacy.
Unit & Format Converters
7 toolsConvert lengths, masses, temperatures, engineering units, electrical units, and cURL API commands instantly with high-precision arithmetic and offline-first privacy.
Time & Date Utilities
6 toolsParse Unix epoch timestamps, calculate date differences, build cron schedules, and convert UTC dates to local time formats 100% client-side in your browser.
Text & String Utilities
20 toolsCount words, convert text cases, parse color values, generate ASCII art, and transform strings offline in your browser.
SEO & Crawler Utilities
8 toolsFree online seo and crawler tools to preview Google SERP snippets and OpenGraph social cards, validate robots.txt crawl directives and XML sitemaps, and audit JSON-LD structured data 100% locally in your browser with zero server tracking.
About Telekit Tools
Built to replace bloated, ad-heavy tool sites with instant, privacy-focused utilities.
100% Client-Side Privacy
PDF processing, image conversions, formatters, and hash generators run entirely inside your browser. No files or inputs ever touch a server.
Unique Group Link Checkers
The only place to instantly preview Telegram and WhatsApp group names, member counts, and avatars before joining or sharing invites.
No Ads, No Sign-up
Zero accounts, zero paywalls, zero pop-ups. Clean, lightweight developer tools ready the moment you open the page.
Why Choose Client-Side Developer Tools?
Compare the security, speed, and privacy of in-browser execution versus legacy cloud-based utilities.
| Dimension | Telekit Tools (Client-Side) | Traditional Cloud Tools |
|---|---|---|
| Data Transmission | ✓ Zero server uploads; in-memory only | Transmitted to remote cloud servers |
| Processing Latency | ✓ 0ms network latency; instant execution | Network roundtrips & server queues |
| Sensitive Data Safety | ✓ Safe for private keys, tokens & JSON | Risk of server logging and access traces |
| Offline Usability | ✓ Full offline capability once cached | Completely disabled without active internet |
| Usage Limits & Caps | ✓ 100% Free with zero caps or queues | File size quotas, hourly limits, paywalls |
| Group Link Checkers | ✓ Anonymous Telegram & WhatsApp preview | Not supported by developer utility suites |
Frequently Asked Questions
Everything you need to know about our privacy architecture, offline support, and developer utilities.
Are all free online developer tools on Telekit completely free to use?
Yes, all 88+ free online developer tools on Telekit are 100% free with no sign-up required, no paywalls, and no hidden fees. We believe essential developer and productivity utilities should be universally accessible to everyone.
Do you store or log my files, code, or personal data?
No. All formatters, compressors, generators, cryptographic hashers, and calculators execute 100% client-side in your browser using JavaScript, WebAssembly, and browser-native Web APIs. Your code, documents, and inputs never touch a remote server.
What makes Telekit different from other free online developer tools like 10015.io or IT-Tools?
Telekit combines comprehensive client-side utilities with exclusive zero-login Telegram and WhatsApp invite link verification. We enforce zero server retention, serve zero third-party ads, require no user accounts, and provide instant Cmd/Ctrl+K keyboard search and DevToys-style smart clipboard auto-detection across all tools.
How do I check if a Telegram or WhatsApp link is active?
Simply paste the invite link into our Telegram Link Checker or WhatsApp Link Checker. Our service safely resolves the public metadata (group title, member count, avatar, and active status) without revealing your personal identity or requiring you to join the group.
Can I use Telekit Tools offline without an internet connection?
Yes. All core developer utilities—including JSON formatters, UUID generators, Base64/URL encoders, password generators, math calculators, and image compressors—run completely offline once loaded in your browser.
Is Telekit Tools safe for sensitive enterprise credentials and proprietary code?
Yes. Because code execution occurs strictly within your local browser sandbox and never transmits network payloads to our backend, proprietary API keys, database connection strings, JWT tokens, and internal JSON objects remain entirely confidential on your machine.
What file formats and conversions are supported?
Telekit supports tabular formats (CSV, JSON, YAML, XML, SQL), image formats (JPG, PNG, WebP, SVG), document formats (PDF merge and compression), and data encodings (Base64, URL percent-encoding, Hex, Binary, Morse Code, and HTML entities).
How fast is client-side browser execution compared to remote servers?
Client-side execution eliminates HTTP request-response roundtrip latency, delivering instantaneous zero-millisecond processing. Large transforms and image rasterization utilize native browser WebAssembly and Canvas pipelines directly on your local CPU/GPU.
How does the Smart Clipboard Auto-Detect (Alt+P) feature work?
Inspired by modern developer desktop tools like DevToys, pressing 'Alt+P' or clicking 'Smart Detect' inspects your clipboard payload using client-side heuristics. If it detects JSON data, UUIDs, JWT tokens, Base64 strings, Unix timestamps, Hex colors, SQL queries, or Telegram/WhatsApp invite links, it will automatically identify the format and route you directly to the appropriate utility.
What keyboard shortcuts are supported for rapid catalog navigation?
You can press '/' or 'Cmd+K' ('Ctrl+K') to search the 90+ tools catalog, use Arrow Up/Down and Enter to select suggestions, 'Alt+V' to switch between 3-Column Grid View and Compact List View, 'Alt+R' to jump to a random utility (Surprise Me), 'Alt+P' for Smart Clipboard Detect, 'Alt+S' to copy the portal URL, 'Alt+K' or '?' for the Keyboard Shortcuts modal, and 'Escape' to clear searches or close dialogs.