Free online tools
Free web tools for SEO, code and everyday tasks.
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Website Status Checker
Check whether a website is up and reachable, or down for everyone. -
Ping
Measure how long a server takes to respond, to spot slow or unreachable hosts. -
IP to Hostname
Reverse-lookup an IP address to find the hostname it points back to. -
Hostname to IP
Resolve a domain or hostname to the IP address it currently points at. -
IP Information
Look up an IP address's approximate location, ISP and network owner. -
MX Lookup
See which mail servers accept email for a domain, in priority order. -
User Agent Finder
Show your browser's full user agent string, plus the browser, OS and device it describes. -
What's My IP
See the public IP address that websites see when you connect. -
DNS Lookup
Fetch a domain's A, AAAA, MX, TXT and CNAME records in one go. -
Open Port Checker
Test whether a TCP port on a host is open and accepting connections. -
IP Subnet Calculator
Work out the network, broadcast address, mask and usable host range for any subnet. -
HTML Entity Encode
Turn <, >, & and quotes into HTML entities so code displays as text instead of running. -
HTML Entity Decode
Convert entities like & and " back into readable characters. -
URL Encoder
Percent-encode spaces, symbols and accented letters so a URL or query value travels safely. -
URL Decoder
Turn %20-style percent-encoding back into a readable URL or parameter. -
Text to Binary
Show the 8-bit binary code behind every character of your text. -
Binary to Text
Decode groups of 0s and 1s back into readable text. -
Text to Base64
Encode text as Base64 for use in JSON, headers, data URIs and config files. -
Base64 To Text
Decode a Base64 string to reveal the text inside it. -
ROT13 Encoder
Shift every letter 13 places to hide spoilers or puzzle answers in plain sight. -
ROT13 Decoder
Shift ROT13-scrambled letters back 13 places to read the original message. -
Unicode to Punycode
Convert an internationalised domain like münchen.de into its xn-- form for DNS. -
Punycode to Unicode
Turn an xn-- domain from logs or WHOIS back into the characters people type. -
Encode Quoted Printable
Encode accented letters and symbols the way email (MIME) expects them. -
Decode Quoted Printable
Clean up =C3=A9-style email source back into the original readable text. -
Image Rotate
Fix sideways photos by rotating them in 90-degree steps, right in your browser. -
Image to Grayscale
Convert any picture to black and white (shades of grey) and save the result. -
Image Compressor
Shrink image files with a quality slider and a before/after size comparison. -
Image Resizer
Scale an image to exact pixel dimensions, with the option to keep its proportions. -
QR Code Generator
Turn a link into a QR code that any phone camera can scan, ready to download. -
QR Code Reader
Upload a screenshot or photo of a QR code and read the data inside without a phone. -
Image to Base64
Convert an image into a Base64 data URI to embed directly in HTML or CSS. -
JPG to PNG
Re-save a JPG as a lossless PNG for editing, logos and screenshots. -
JPG to WEBP
Convert JPG photos to WebP for smaller files and faster-loading pages. -
PNG to JPG
Convert a PNG to a much smaller JPG, ideal for photos on the web and in email. -
PNG to WEBP
Convert PNG graphics to WebP and keep transparency with a smaller file size. -
WEBP to JPG
Turn a WebP image into a JPG that opens in every editor and print service. -
WEBP to PNG
Turn a WebP image into a widely supported PNG, keeping transparent backgrounds. -
Image OCR
Extract editable text from a screenshot, scan or photo of a document. -
Markdown To HTML
Convert Markdown into clean HTML for websites, emails and CMS fields. -
HTML To Markdown
Convert HTML into Markdown for docs, static-site generators and note apps. -
CSV To JSON
Turn spreadsheet rows into a JSON array, using the header row as keys. -
JSON To CSV
Flatten a JSON array into CSV rows that open in Excel or Google Sheets. -
JSON to XML
Map JSON objects and arrays to XML elements, with control over the root name and indentation. -
XML To JSON
Convert an XML document or feed into JSON that is easy to use in code. -
HTML Minifier
Strip comments and extra whitespace from HTML to cut page weight. -
CSS Minifier
Compress a stylesheet by removing comments and unneeded whitespace. -
JS Minifier
Compress JavaScript by removing comments, whitespace and other unneeded characters. -
HTML Formatter
Re-indent messy or minified HTML so nested elements are easy to follow. -
CSS Formatter
Expand minified CSS so each rule and declaration sits on its own line. -
JS Formatter
Restore line breaks and indentation to minified JavaScript so you can read it. -
RGB To Hex
Convert red, green and blue values into a HEX colour code with a live preview. -
Hex To RGB
Convert a HEX colour code into its red, green and blue values. -
JSON Beautifier
Pretty-print, validate and sort the keys of minified JSON so it is easy to read. -
JSON Validator
Check whether JSON parses and find the exact spot where it breaks. -
Timestamp Converter
Convert Unix timestamps to readable dates and back again. -
On-Page SEO Checker
Audit any page's title, meta tags, headings, images, links, canonical and structured data in one report. -
AI Crawler Checker
See which AI crawlers, such as GPTBot, ClaudeBot and Google-Extended, your robots.txt allows or blocks. -
SERP Snippet Preview
Preview how your title and meta description look in Google results, with pixel-width truncation checks. -
Schema Markup Generator
Build JSON-LD structured data for FAQ, Article, Organization, Local Business and Breadcrumb markup. -
HTML Code Editor
Write HTML, CSS and JavaScript and see a live preview update as you type. -
SEO Tags Generator
Generate title, meta description and Open Graph tags ready to paste into your page. -
Twitter Card Generator
Generate the meta tags that control how your links look when shared on X (Twitter). -
Privacy Policy Generator
Draft a privacy policy for your website from a few business details. -
Terms of Service Generator
Draft terms of service for your website or app from a few business details. -
Robots.txt Generator
Build a robots.txt file with per-crawler rules, crawl delay and your sitemap URL. -
HTACCESS Redirect Generator
Write the Apache .htaccess rule to redirect a moved page or a whole domain. -
Lorem Ipsum Generator
Generate as many lorem ipsum words or paragraphs as your layout needs. -
HTML Tags Stripper
Remove every HTML tag and keep only the plain text. -
JS Obfuscator
Make JavaScript hard for people to read while it still runs the same way. -
SQL Beautifier
Lay out long SQL queries with indented keywords, joins and conditions. -
Wheel Color Picker
Pick any colour from a colour wheel and get its HEX, RGB and HSL values. -
Online SMTP Test
Test an SMTP server's host, port, encryption and login by sending a real test email. -
GZIP Compression Test
Check whether a web server really sends compressed (gzip) responses. -
Source Code Downloader
View and copy the raw HTML a server returns for any URL. -
Text Cleaner
Remove extra spaces, stray line breaks, smart quotes and hidden formatting in one go. -
Email Extractor
Pull every email address out of a block of text or page source. -
URL Extractor
List every link found in a block of text, an email or page source. -
Word Count
Count words and letters live as you type, to stay within any length limit. -
Text Separator
Split comma-separated or other delimited text so each item gets its own line. -
Text To Slug
Turn a title into a clean, lowercase, hyphenated URL slug. -
Duplicate Lines Remover
Delete repeated lines from a list and keep one copy of each. -
Line Break Remover
Join text copied from PDFs and emails back into normal flowing paragraphs. -
Text Replacer
Find a word or phrase and replace every occurrence in one click. -
Text Reverser
Reverse the order of characters in any piece of text. -
Word Density Counter
See how often each word appears, to spot overused terms and check keyword focus. -
Palindrome Checker
Check whether a word or phrase reads the same forwards and backwards. -
Case Converter
Switch text between UPPER, lower, Title, Sentence and other cases in one click. -
Shuffle Text Lines
Put a list of lines into random order for draws, quizzes and test data. -
Text Repeater
Repeat a word or phrase as many times as you need, ready to copy. -
Paste & Share Text
Publish a snippet, log or note and share it with a short link. -
Email Validator
Check a list of email addresses and flag the ones that are not valid. -
Random Number Generator
Pick one or more random numbers within any range you set. -
Password Generator
Create strong random passwords with the length and character types you choose. -
Password Strength Test
Rate a password and see which strength rules it meets or misses. -
MD5 Generator
Create the MD5 checksum of any text, for comparing data and spotting changes. -
SHA Generator
Hash text with SHA-256 or SHA-512 for integrity checks and signatures. -
Bcrypt Generator
Create a salted bcrypt password hash for test data or configuration. -
Hash Generator
Hash text with MD5, SHA-1, SHA-2, SHA-3, RIPEMD, Whirlpool and more. -
UUIDv4 Generator
Generate random version 4 UUIDs for database keys and test data. -
Data Storage Converter
Convert between bits, bytes, KB, MB, GB, TB and larger storage units. -
Length Converter
Convert between metric and imperial lengths: mm, cm, m, km, inches, feet, miles and more. -
Speed Converter
Convert speeds between km/h, mph, m/s, knots and other units. -
Temperature Converter
Convert temperatures between Celsius, Fahrenheit, Kelvin and other scales. -
Weight Converter
Convert weights between kilograms, pounds, ounces, stones and more. -
Domain Generator
Get domain name ideas built around your keyword. -
Domain WHOIS
See who registered a domain, with which registrar, and when it expires. -
URL Parser
Split a URL into its protocol, host, path, query string and fragment. -
SSL Checker
Check whether a site's SSL certificate is valid, who issued it and when it expires. -
HTTP Headers Parser
See the HTTP response headers a server sends back for any URL. -
URL Unshortener
Follow a short link and reveal its final destination before you click it. -
Redirect Checker
Check whether a URL redirects, and which address it finally lands on. -
HTTP Status Code Checker
See the HTTP status code (200, 301, 404 and so on) a URL returns. -
Glitch Text Generator
Turn text into glitchy Zalgo text you can paste into bios, posts and chats. -
Bubble Text Generator
Put each letter in a bubble using Unicode characters you can copy anywhere. -
Upside Down Text Generator
Flip your text upside down with Unicode lookalike characters. -
Currency Converter
Convert between currencies using the European Central Bank's daily reference rates. -
Dice Roller
Roll a virtual dice for board games and quick decisions. -
Virtual Coin Flip
Flip a virtual coin and keep a running tally of heads and tails. -
Aim Trainer
Warm up your mouse aim with on-screen targets and see your hits and accuracy. -
Age Calculator
Work out an exact age in years, months and days from a date of birth. -
Between Dates Calculator
Count the days, weeks and months between any two dates. -
BMI Calculator
Calculate body mass index in metric or imperial units and see its category. -
Compound Profit Calculator
See how an amount grows over time when returns are reinvested. -
Interest Calculator
Work out the interest earned or owed on an amount, rate and term. -
GPA Calculator
Calculate your credit-weighted grade point average from your courses. -
Countdown Timer
Set hours, minutes and seconds and count down to zero. -
Stopwatch
Time anything to the millisecond with a simple online stopwatch. -
Scientific Calculator
Trig, logs, roots, powers and brackets, with keyboard or on-screen buttons. -
World Clock
Compare the current local time and UTC offset of countries around the world. -
What's My Browser
See which browser and version you are using, for support requests and bug reports. -
Credit Card Validator
Check whether a card number is correctly formed, without contacting any bank. -
Date Picker Calendar
A simple calendar to browse months and years and pick a date. -
YouTube Thumbnail Downloader
View and save the thumbnail image of a YouTube video.
AI Crawler Checker
See which AI crawlers, such as GPTBot, ClaudeBot and Google-Extended, your robots.txt allows or blocks.
AI Crawler Checker
AI companies use their own crawlers to collect content for training models and to fetch pages for AI-powered search answers. Each one follows the rules in your robots.txt file under its own name. This tool reads your robots.txt and shows, crawler by crawler, whether it may fetch your site, so you can confirm your choices are actually in effect.
How to use AI Crawler Checker
- Enter a domain or a page address, such as example.com or https://example.com/blog.
- Click Check crawlers. The tool downloads the site's robots.txt file.
- Read the table: Allowed means the crawler can fetch the address you entered, Blocked means it cannot, and Partly blocked means some paths on the site are off limits to it.
- To change the result, edit your robots.txt. The Robots.txt Generator on this site can help you write the rules.
When it comes in handy
- Confirming that a block you added for AI training crawlers is working.
- Making sure you have not accidentally blocked AI search crawlers that could send you visitors.
- Seeing how other publishers in your field handle AI crawlers.
Frequently asked questions
- Does blocking a crawler in robots.txt stop it completely?
- Robots.txt is a set of instructions, not a lock. The major AI companies say their crawlers respect it, but it cannot stop a crawler that chooses to ignore it. For that you need server-level blocking.
- What is the difference between a training crawler and a search crawler?
- Training crawlers, such as GPTBot and ClaudeBot, collect content to improve AI models. Search and user crawlers, such as OAI-SearchBot or ChatGPT-User, fetch pages to answer a question right now and can link back to you. Many sites block the first kind and allow the second.
- Why are Googlebot and Bingbot in the list?
- They are shown for comparison. Blocking them removes your site from Google or Bing search. Google-Extended is different: blocking it does not affect Google Search rankings.
