Useful online tools, without the fuss.
Check a website or domain, diagnose DNS and email, calculate transfers and quickly understand common internet errors.
Find a solution quickly
What do you need to fix?
Choose an issueA website is down or redirects unexpectedlyCheck HTTP status, HTTPS, redirects, basic SEO, robots, sitemap and security headers.Choose an issueMy email ends up in spam or never arrivesCheck public SPF and DMARC records and optionally the DKIM selector for your domain.Choose an issueI need to inspect suspicious email headersRead SPF, DKIM, DMARC, server hops and From/Reply-To/Return-Path mismatches locally.Choose an issueA DNS change is not yet visibleInspect current A, AAAA, CNAME, MX, TXT, NS, SOA and CAA records and their TTL.Choose an issueWhen was a domain registered or when does it expire?Check current public RDAP registration, expiry, registrar, nameservers, status and DNSSEC.Choose an issueMy internet is slow — what am I actually getting?Measure download, upload, ping and jitter and instantly see whether it is enough for 4K video, video calls and gaming.Choose an issueWi-Fi is slow or unstableDistinguish signal, frequency band, congestion, device, router and internet-plan limitations.Choose an issueHow long will a download take?Estimate transfer time from file size and connection speed.Choose an issueA message or link looks suspiciousCheck the domain, urgency, login page, attachments and other phishing signs before acting.Choose an issuePort forwarding or remote cameras do not workUnderstand whether CGNAT may be responsible and what you can do.
Quick tools
All tools →Calculators and browser utilities
ToolInternet speed testFree internet speed test with no app: measure download, upload, ping and jitter, and see whether your connection is good enough for 4K video, video calls and gaming.ToolMbps ↔ MB/s calculatorConvert Mbps to MB/s and back instantly. Table for 10 to 10,000 Mbps with download times for 1 GB, 4 GB and 50 GB files, plus a real speed test.ToolDownload time calculatorEstimate how long a file download will take based on its size and your connection speed.ToolMy public IP addressSee the public IP address with which your request reached splet.me. We do not save it to a user profile.ToolIPv4 CIDR calculatorCalculate the network address, subnet mask, wildcard mask, broadcast and usable host range from an IPv4 CIDR value locally.ToolIPv6 CIDR calculatorCalculate canonical IPv6 notation, network prefix, first and last addresses, and address count from an IPv6 CIDR value locally.ToolJSON formatter and validatorFormat and validate JSON locally in your browser. Your JSON is not sent to the server for formatting.ToolStrong password generatorGenerate a random password locally using the Web Crypto API. The password is not sent to splet.me.ToolWord and character counterCount words, characters, characters without whitespace, lines and approximate sentences locally in your browser.
HTTP status codes
All codes →A site shows an error number?
500Internal Server ErrorUnexpected server error.503Service UnavailableThe server is temporarily unavailable.429Too Many RequestsToo many requests; wait and retry.401UnauthorizedA login or token is required.400Bad RequestMalformed request.301Moved PermanentlyPermanent redirect.522Cloudflare: Connection Timed OutThe origin didn't respond in time.521Cloudflare: Web Server Is DownThe origin refused the connection.
Understand the issue
All guides →When browsers or Wi-Fi fail
GuideERR_NAME_NOT_RESOLVED: what it means and how to fix itChrome shows ERR_NAME_NOT_RESOLVED? Check DNS, domain, local cache and network, and distinguish a public DNS issue from a problem on one device.GuideERR_SSL_PROTOCOL_ERROR: meaning and HTTPS troubleshootingERR_SSL_PROTOCOL_ERROR means Chrome could not establish a valid HTTPS/TLS session. Check the certificate, TLS, proxy, CDN and HTTPS inspection.GuideSPF, DKIM and DMARC: what's the difference?An accessible guide to SPF, DKIM and DMARC, what each mechanism checks, how they work together, the DNS records needed and common mistakes.GuideDNS_PROBE_FINISHED_NXDOMAIN: meaning and fixesLearn what DNS_PROBE_FINISHED_NXDOMAIN means and distinguish a mistyped address, DNS issue or domain configuration problem.GuideYour connection is not private — what should you do?What the browser's 'Your connection is not private' warning means and when you must not proceed.GuideWhy is my Wi-Fi slow?Slow Wi-Fi is not always slow internet. Check signal, band, congestion, devices, router and subscription systematically.
Why use splet.me?
No false certainty
A technical signal is not proof of business legitimacy. We make that distinction clear.
Local processing
IPv4/IPv6 CIDR, JSON, Base64, URL, timestamp, passwords and word counting run in your browser.
Practical next steps
Guides distinguish symptoms from causes and explain what to check first.