Tool directory
All 39 free tools
Grouped into 3 suites. Every tool has its own page, works without an account, and keeps nothing you enter.
Email Suite
Audit and build the DNS records that decide whether your email is trusted — SPF, DKIM, DMARC, BIMI and MTA-STS — then score the whole posture.
AuthenticationSPF Record CheckerAudit RFC 7208 SPF records, count DNS lookups against the 10-lookup quota and parse every mechanism and qualifier.Open tool →DNS GeneratorsSPF Record GeneratorBuild a valid SPF TXT record from your providers and IP ranges, then copy it straight into DNS.Open tool →AuthenticationDKIM Key CheckerLook up DKIM public keys by selector, decode the tags and flag keys weaker than 2048-bit RSA.Open tool →DNS GeneratorsDKIM Record GeneratorGenerate a 2048-bit RSA key pair in your browser and get the matching DNS TXT record — the private key never leaves the page.Open tool →AuthenticationDMARC Policy CheckerVerify your DMARC policy and alignment modes, and see exactly what receivers do with mail that fails.Open tool →DNS GeneratorsDMARC Record GeneratorWalk from p=none to p=reject safely: build the DMARC record with reporting addresses, percentage rollout and alignment.Open tool →AuthenticationBIMI Logo CheckerInspect BIMI DNS records, preview the SVG brand logo and check the Verified Mark Certificate behind it.Open tool →DNS GeneratorsBIMI Record GeneratorGenerate the BIMI TXT record and validate that your logo meets the SVG Tiny P/S profile mailbox providers require.Open tool →DNS GeneratorsMTA-STS GeneratorProduce the MTA-STS DNS record, the .well-known policy file and a TLS-RPT record so mail to your domain stays encrypted in transit.Open tool →DiagnosticsEmail Header AnalyzerPaste raw RFC 5322 headers to trace every relay hop, measure delays and see which authentication checks passed.Open tool →DiagnosticsEmail Security ScoreOne 0-100 score and letter grade for a domain, combining SPF, DKIM, DMARC, BIMI and TLS in a single pass.Open tool →
Link & URL
See where a link really goes before you click it: expand redirect chains, inspect certificates, check domain age and decode QR codes.
Threat DetectionURL ScannerCheck any URL for lookalike domains, homograph tricks, odd entropy and known bad reputation before you open it.Open tool →Threat DetectionSafe Link CheckerInspect a suspicious link, strip its tracking parameters and preview where it lands — without visiting it yourself.Open tool →DiagnosticsRedirect CheckerExpand short links and follow every hop — 301, 302, 307, 308 and meta refresh — with loop detection and headers.Open tool →DiagnosticsDomain Age CheckerQuery ICANN RDAP for a domain’s real registration date, registrar and age — brand-new domains are worth a second look.Open tool →InfrastructureSSL Certificate CheckerRead a live TLS handshake: issuer, subject alternative names, cipher suite and exactly how many days until expiry.Open tool →Threat DetectionQR Code ScannerDecode a QR code image or payload to reveal the URL hidden inside it, then trace where that URL goes.Open tool →UtilitiesQR Code GeneratorMake high-resolution QR codes for links, text or WiFi with custom colours and error correction, then download SVG or PNG.Open tool →UtilitiesPassword GeneratorGenerate strong random passwords, memorable passphrases and PINs with crypto.getRandomValues(), with live entropy and cracking-time estimates.Open tool →UtilitiesPassword Entropy CheckerMeasure a password’s entropy in bits and see how long it would resist a GPU cracking rig. Typed characters never leave your browser.Open tool →UtilitiesSecurity Badge GeneratorGenerate an embeddable SVG trust badge for your own site showing TLS and DMARC status.Open tool →
Calculators
Exact age and date arithmetic, timesheets and hours, GPA and course grades, concrete volumes, subnet maths and unit conversion — all in-browser.
Date & TimeAge CalculatorExact age in years, months and days plus total weeks, days, hours and minutes, next birthday countdown, day of the week you were born and leap days lived.Open tool →Date & TimeChronological Age CalculatorYears, months and days between date of birth and an assessment date — the format required by clinical reports, psychometric scoring and school admissions.Open tool →Health & FamilyBaby Age CalculatorYour baby’s age in days, weeks and months with developmental stage, plus corrected (adjusted) age for babies born preterm.Open tool →Date & TimeAge Calculator on a DateHow old someone was — or will be — on any specific past or future date. Useful for eligibility cut-offs, forms, records and anniversaries.Open tool →Date & TimeAge Calculator TodayEnter one date of birth and get your age as of today, recomputed live in your own timezone. No second date, no settings.Open tool →Exam EligibilityUPSC Age CalculatorYour age on the 1 August cut-off for the UPSC Civil Services Examination, with a per-category verdict, eligible date-of-birth window and attempts remaining.Open tool →Date & TimeAge Calculator IndiaAge from a DD/MM/YYYY date of birth in the format Indian forms, exams and government portals ask for, with the completed-years rule and cut-off dates.Open tool →Health & FamilyChild Age CalculatorYour child’s age in years, months, weeks and days, plus age in completed months for growth charts and school-entry cut-off dates.Open tool →Health & FamilyGestational Age CalculatorGestational age in weeks and days with the estimated due date, trimester, term classification and milestone dates — from LMP, conception date or a known due date.Open tool →Health & FamilyDog Age CalculatorYour dog’s age in human years using the AKC size-banded chart rather than the debunked “multiply by seven” rule, with life stage and the epigenetic-clock figure.Open tool →Date & TimeDate CalculatorAdd or subtract days, weeks, months and years from any date, or measure the span between two dates in days, weeks, months, weekdays and weekend days.Open tool →Date & TimeTime CalculatorAdd and subtract hours, minutes and seconds, or find the elapsed time between two clock readings — including spans that cross midnight.Open tool →Date & TimeHours CalculatorA weekly timesheet that totals worked hours from clock-in and clock-out times, subtracts breaks, splits overtime and multiplies by your pay rate.Open tool →EducationGPA CalculatorTerm and cumulative GPA on the unweighted 4.0 scale or a weighted 5.0 scale with honours, AP and IB bumps — plus the average you still need to hit a target.Open tool →EducationGrade CalculatorYour weighted course percentage from homework, quizzes and exams, the letter grade it maps to, and the mark you need on the final to reach the grade you want.Open tool →ConstructionConcrete CalculatorCubic yards or cubic metres for slabs, footings, walls, round columns and stairs, with waste allowance, bag counts, mix ratios and an estimated ready-mix cost.Open tool →NetworkingSubnet CalculatorIPv4 CIDR maths — network, broadcast, mask, wildcard, usable host range and binary view — plus equal-size subnet splitting and IPv6 prefix arithmetic.Open tool →Unit ConversionConversion CalculatorConvert length, weight, temperature, area, volume, speed, pressure, energy, power, time, data and angle — one exact factor table, every unit shown side by side.Open tool →
Provider & service guides
Per-provider SPF and DKIM setup, per-service redirect expansion, and published domain security reports.
Email providers (20)
Google Workspace (Gmail)Microsoft 365 / Office 365 (Exchange Online)SendGrid (Twilio)Mailchimp (Intuit)Amazon Simple Email Service (SES)HubSpotZoho Mail & Zoho WorkplaceBrevo (formerly Sendinblue)Postmark (ActiveCampaign)KlaviyoSalesforce Marketing Cloud & PardotShopify Email & Store NotificationsMailgun (Sinch)ActiveCampaignProton Mail (Custom Domains)Resend (Modern Developer Email API)Fastmail (Custom Domains)Constant ContactCampaign Monitor (Marigold)Zendesk Support & Ticketing