Web & Network tools
Lookups, diagnostics and SEO checks for domains and servers.
56 of the 65 run entirely in your browser — nothing uploaded, working offline — and every page says which before you pick a file.
65 tools
- Cron Expression ParserExplain a cron expression in plain English + show the next 5 fires.
- Cron Expression GeneratorBuild a cron expression from minute / hour / day / month dropdowns.
- Subnet CalculatorCIDR → range, broadcast, mask, host count.
- cURL ConverterConvert a curl command to fetch / axios / Python requests / Node.
- User-Agent ParserDecode a User-Agent string into browser, OS, device.
- HTTP Status Code ReferenceLook up any HTTP status code with description and use cases.
- MIME Type LookupLook up the MIME type for a file extension and vice versa.
- IP Address LookupGeolocate an IP address: country, city, ISP, ASN.
- DNS LookupA, AAAA, MX, TXT, NS, CNAME records for any domain.
- WHOIS LookupDomain registrar, creation date, expiry, name servers.
- SSL Certificate CheckerInspect a site's SSL certificate: issuer, expiry, chain.
- robots.txt GeneratorBuild a robots.txt with allow/disallow rules per user-agent.
- sitemap.xml GeneratorBuild a sitemap.xml from a list of URLs.
- Schema.org Markup GeneratorGenerate JSON-LD for Article, FAQPage, BreadcrumbList, Product, Recipe, Event.
- Meta Tag GeneratorGenerate <title>, description, OG tags, Twitter card meta tags.
- Stopwatch / TimerOnline stopwatch, countdown timer, and Pomodoro — runs in your browser.
- CSS Box-Shadow GeneratorVisually configure CSS box-shadow with multiple layers.
- CSS Border-Radius GeneratorConfigure all four corners individually.
- CSS Flexbox GeneratorBuild flexbox layouts visually; copy CSS.
- CSS Grid GeneratorBuild CSS grid layouts visually.
- Pomodoro Focus Timer25/5 focus + break cycles, customizable durations, persistent state.
- Event Countdown TimerLive countdown to any future date — Christmas, birthday, deadline.
- Working Days Between DatesBusiness days between two dates, excluding weekends + custom holidays.
- Time Card CalculatorTotal weekly hours from clock-in/out times with overtime.
- Meeting Planner Across Time ZonesFind overlapping working hours for a team across global time zones.
- Sunrise / Sunset CalculatorCompute sunrise, sunset, golden hour, twilight for any location.
- Moon Phase CalculatorCurrent and historical lunar phase + illumination + age.
- Unix Timestamp Difference CalculatorDiff two Unix timestamps in seconds / minutes / hours / days.
- Age Difference CalculatorYears, months, days between two birthdates.
- Date Add / Subtract CalculatorAdd or subtract days, weeks, months, years from a date.
- Timezone Difference CalculatorHours difference between any two named timezones.
- Date Format ConverterReformat dates: ISO 8601, US, EU, RFC 2822, Unix, custom formats.
- Keyword Density CheckerWord frequency, keyword density %, top n-grams for SEO content audit.
- Google SERP / Meta PreviewPreview how your title + description + URL look in Google search results.
- Open Graph / Twitter Card PreviewPreview how your URL appears when shared on Facebook, Twitter, LinkedIn.
- Headline AnalyzerScore a headline for length, sentiment, power words, emotional impact (CoSchedule-style).
- Email Subject Line TesterScore email subject lines for length, spam triggers, urgency words.
- Readability Score (Flesch / Lexile)Flesch Reading Ease, Flesch-Kincaid grade level, Lexile, Gunning Fog.
- Conversion Rate CalculatorConversion rate, CR uplift, revenue impact from your funnel numbers.
- A/B Test Sample Size & SignificanceRequired sample size + statistical significance from observed conversions.
- ROAS / ROI Marketing CalculatorReturn on ad spend, customer acquisition cost, blended CPA.
- Maximum CPC Bid CalculatorMax profitable CPC bid from conversion rate + AOV + target margin.
- Best Time to Send EmailBest send-time recommendations by industry + audience timezone.
- UTM Campaign URL BuilderCompose Google Analytics / GA4 UTM-tagged URLs.
- URL Slug OptimizerGenerate SEO-friendly URL slugs from titles — multilingual support.
- SEO Word Counter & Character LimitsWord count + char count + Twitter/LinkedIn/title-tag/meta-desc limits.
- Social Media Hashtag GeneratorSuggest relevant hashtags from a topic for Instagram, TikTok, X.
- What's My IP AddressShow your public IPv4 / IPv6 address with one click.
- What's My Screen ResolutionSee your monitor resolution, pixel density, and viewport size.
- What's My User AgentShow your browser User-Agent string + parsed browser/OS/device.
- Browser Info / FingerprintDetailed browser, OS, hardware, plugin, font, and canvas fingerprint.
- My Location / GeolocationUse the browser geolocation API to display your latitude/longitude/altitude.
- Internet Speed TestTest download + upload speed + latency against our servers.
- HTTP Ping / Latency TestMeasure latency to any URL with N samples + jitter.
- Cookie Viewer / EditorList all cookies on the current page with name, value, expiry, secure flags.
- Page Speed TesterLighthouse-grade performance audit for any URL — score, LCP, CLS, FID.
- Mobile-Friendly TesterCheck if a URL is mobile-responsive — viewport, tap targets, font sizes.
- Broken Link CheckerCrawl a URL and report 404s, 5xx, redirects, slow links.
- Domain Age CheckerHow old is a domain? Created, updated, expires from WHOIS.
- Axiomatic Authority ScoreOur own SEO authority metric from age, indexed pages, and link-graph signals.
- Online TimerQuick countdown timer — type seconds and go. Sound + browser notify.
- Online Alarm ClockSet an alarm time — browser notify + sound when it fires.
- Printable Calendar GeneratorGenerate a monthly or yearly calendar PDF — pick year, start day, theme.
- Week Number CalculatorFind ISO week number for any date + week-start/end dates.
- WhatsApp Direct Link GeneratorBuild click-to-chat WhatsApp links with pre-filled message.