Free Online Tools

Two hundred fourteen free online tools that run privately in your browser: no sign-up, no uploads, no waiting. Pick a family below — every tool lives inside its own designed section.

Main Tools

The most popular and useful tools, picked from every family.

18 tools
IP in CIDR Range Checker Download Time Calculator SPF Record Builder DMARC Record Builder AES Encrypt / Decrypt Tool RSA Key Pair Generator .htaccess Redirect Generator llms.txt Generator API Request Code Generator Dockerfile Generator PC Power Supply Calculator RAID Capacity Calculator GZIP Text Compressor IEEE 754 Float Converter SLA Uptime Calculator Server Log Analyzer AI Prompt Builder Prompt Token Estimator

Networking & IP

Addresses, protocols, and connections

11 tools
IPv6 Expander / Compressor IP Address Validator IP in CIDR Range Checker Port Number Lookup HTTP Headers Viewer Private / Public IP Classifier WiFi Channel Overlap Checker Download Time Calculator IPv4 Decimal Converter My IP Address Tool DNS Lookup Tool

DNS & Domains

Names, records, and domain setup

7 tools
DNS Zone Record Generator SPF Record Builder DMARC Record Builder Domain WHOIS Lookup Domain Typosquat Generator Punycode Converter DNS TXT Record Parser

Security & Privacy

Encryption, keys, and safe headers

10 tools
SHA-1 Hash Generator SHA-512 Hash Generator AES Encrypt / Decrypt Tool RSA Key Pair Generator Email Header Analyzer Cookie Header Parser Content Security Policy Builder Permissions Policy Builder Strong Password Generator SHA-256 Hash Generator

Webmaster & SEO-tech

Site files, tags, and search setup

18 tools
Robots.txt Tester .htaccess Redirect Generator Cache-Control Header Builder llms.txt Generator HTML Accessibility Checker HTML List Generator HTML Form Generator iFrame Embed Code Generator Keyword Density Checker Meta Tag Generator Meta Title & Description Length Checker Slug Generator Robots.txt Generator Schema Markup Generator UTM URL Builder Readability Checker Keyword Combiner Hreflang Tag Generator

Developer

Code, configs, and dev workflows

36 tools
INI / Properties to JSON Converter Regex Find & Replace Tool Hex Dump Viewer Unicode Escape Converter API Request Code Generator cURL Command Parser .env File Generator Dockerfile Generator Docker Compose Generator .gitignore Generator License File Generator README Generator Changelog Generator SemVer Bump Calculator package.json Generator XPath Tester CSV Validator Code Line Counter JSON Formatter & Validator Base64 Encoder/Decoder URL Encoder/Decoder HTML Encoder/Decoder CSS Minifier JavaScript Minifier HTML Minifier UUID Generator Unix Timestamp Converter JWT Decoder Regex Tester SQL Formatter YAML to JSON Converter JSON to XML Converter Base Converter Cron Expression Builder HTML Table Generator PX to REM Converter

System & Hardware

Machines, circuits, and components

20 tools
JavaScript Benchmark Tool Battery Status Checker GPU Info Checker Display Refresh Rate Tester PC Power Supply Calculator Monitor PPI Calculator RAID Capacity Calculator UPS Runtime Calculator Logic Gate Simulator Boolean Truth Table Generator Karnaugh Map Solver Resistor Color Code Calculator Ohm's Law Calculator LED Series Resistor Calculator Voltage Divider Calculator Capacitor Series / Parallel Calculator Decibel Calculator Wavelength / Frequency Calculator Browser Info Tool Screen Resolution Checker

Data & Encoding

Formats, codes, and checksums

22 tools
Quoted-Printable Encoder / Decoder UTF-8 Byte Counter Base58 Encoder / Decoder Playfair Cipher Tool Rail Fence Cipher Tool GZIP Text Compressor CRC32 Checksum Generator Hamming Code Calculator Gray Code Converter BCD Converter Endianness Converter IEEE 754 Float Converter Two's Complement Converter Bitwise Operation Calculator Text to Binary Converter Binary to Text Converter Morse Code Translator NATO Phonetic Alphabet Converter CSV to JSON Converter JSON to CSV Converter XML Formatter Roman Numeral Converter

Web Performance & Monitoring

Speed, uptime, and reliability

10 tools
SLA Uptime Calculator Uncompressed Image Size Calculator Video Bitrate Calculator Cache Hit Ratio Calculator Server Capacity Estimator Apdex Score Calculator MTBF / MTTR Calculator Server Log Analyzer Resource Hints Generator Image Srcset Generator

AI Tools

Prompts, tokens, and AI workflows

22 tools
AI Prompt Builder AI Prompt Enhancer Prompt Token Estimator AI Token Cost Calculator Context Window Checker System Prompt Generator Few-Shot Example Formatter AI Image Prompt Builder Negative Prompt Generator AI Sampling Parameter Demo AI Glossary Lookup AI Model Comparison Table RAG Chunking Calculator AI Fine-Tuning Cost Estimator AI Conversation Transcript Formatter AI Output Evaluation Rubric Generator Fine-Tuning JSONL Formatter AI Video Prompt Builder AI Music Prompt Builder Embedding Similarity Demo BLEU Score Calculator ROUGE Score Calculator

More Tools

Everyday tools from the original collection — general calculators, text, image and utility tools

58 tools
Acronym Generator Age Calculator Aspect Ratio Calculator Barcode Generator BMI Calculator Case Converter Character Counter Click Speed (CPS) Test Color Contrast Checker Compound Interest Calculator Countdown Timer CSS Border Radius Generator CSS Box Shadow Generator CSS Gradient Generator Date Calculator Date Difference Calculator Dice Roller Discount Calculator Duplicate Word Finder EMI Calculator Favicon Generator Find and Replace Tool Hex/RGB Color Converter Image Color Picker Image Compressor Image Cropper Image Resizer Image to Base64 Converter Image Watermark Tool JPG to PNG Converter Lorem Ipsum Generator Markdown Editor & Preview Meme Generator Percentage Calculator PNG to JPG Converter Pomodoro Timer QR Code Generator Random Name Picker Random Number Generator Reaction Time Test Remove Duplicate Lines Remove Extra Spaces Remove Line Breaks Tool Reverse Text Tool Scientific Calculator Sort Text Lines A-Z Online Stopwatch SVG to PNG Converter Text Compare / Diff Checker Text to Speech Time Zone Converter Tip Calculator Typing Speed Test Unit Converter VAT/GST Calculator Word Counter Word Frequency Counter YouTube Thumbnail Downloader