Calculators, generators, formatters and network checks for the people who keep sites running. No account, no limits — most of them run entirely in your browser.
Look at a host the way the outside world sees it: DNS, certificates, status codes, addresses and ports.
See your public IPv4 and IPv6 address, location, ISP and connection details.
Open tool →Check A, MX, TXT, and NS records for any domain.
Open tool →Verify certificate chain, expiry date, and issuer.
Open tool →Check status codes and redirect chains for any URL.
Open tool →Get network address, broadcast, mask, and usable host range.
Open tool →See every hop on the way to a host, over IPv4 or IPv6, with timings.
Open tool →Ping a host over IPv4 or IPv6 and see latency, jitter and packet loss.
Open tool →Search common TCP/UDP ports by number or service name.
Open tool →Convert storage units and estimate transfer time at a given speed.
Open tool → soonFind out in seconds whether a website is up or down for everyone, or only for you.
soonSee how your website answers from different parts of the world at the same moment.
soonCheck whether visitors in different regions can actually reach your website.
soonOne report on the state of a domain: DNS, mail records and certificates.
soonA quick check-up of a website: is it up, secure and answering as it should?
soonFind the IP address your website is served from.
Work with IPv4 and IPv6 addresses: convert between notations, turn ranges into CIDR blocks, split networks and check where an address is.
Find the country, city, network and owner of any IP address or domain.
Open tool →Check whether a website, its DNS and its mail are ready for IPv6.
Open tool →Turn a CIDR block into an IP range, or a range into the CIDR blocks that cover it.
Open tool →Convert a subnet mask to a CIDR prefix and a wildcard mask, with a full table.
Open tool →Split an IPv4 network into equal smaller subnets.
Open tool →Convert an IPv4 address to a decimal number and back, with hex and binary.
Open tool →Turn an IPv6 prefix into an address range, or a range into CIDR blocks.
Open tool →Split an IPv6 prefix into equal smaller subnets.
Open tool →Shorten an IPv6 address to its standard form or write it out in full.
Open tool →Convert an IPv6 address to a 128-bit decimal number and back.
Open tool →See an IPv4 address in its IPv6 forms: mapped, 6to4 and NAT64.
Open tool →Turn availability targets into minutes of downtime, error budgets and alert thresholds you can act on.
Convert an SLA percentage into allowed downtime per day, month and year.
Open tool →Work out how much of your SLO error budget is burned and how much is left.
Open tool →Get multi-window burn-rate alert thresholds and PromQL from an SLO target.
Open tool →Combine the SLAs of dependent and redundant services into one real figure.
Open tool →Estimate the business cost of an outage per minute, hour and incident.
Open tool →Compute an Apdex score from request counts or a list of response times.
Open tool →A reference table of allowed downtime for every common availability target.
Open tool →Pick a heartbeat interval and grace period that avoid false alerts.
Open tool →Plan rotations, measure how the pager treats your team, and build the alerts and payloads they receive.
Compute MTTA, MTTR and MTBF from a list of incident timestamps.
Open tool →Design a fair on-call rotation and export it as a calendar file.
Open tool →Find working-hour overlap and coverage gaps across time zones.
Open tool →Quantify pager noise: interrupted hours, night pages and yearly cost.
Open tool →Build and preview a Slack incident alert, then copy the Block Kit JSON.
Open tool →Validate and format a webhook payload and list every field path.
Open tool →Build PromQL queries from a form, with a cheat sheet of common patterns.
Open tool →Templates and builders for the paperwork of an incident: severity levels, escalation, status updates, the write-up.
Produce a structured, blameless incident postmortem in Markdown.
Open tool →Build a SEV-level matrix with definitions and response targets.
Open tool →Generate clear customer-facing status updates for each incident stage.
Open tool →Design a tiered escalation chain and see the worst-case response time.
Open tool →Make raw log lines readable: test patterns, clean up escape codes, flatten JSON, line up timestamps.
Test a pattern against sample text with live match highlighting.
Open tool →Build and test Logstash grok patterns with live field extraction.
Open tool →Reflow collapsed one-line stack traces into a readable format.
Open tool →Flatten nested JSON logs to dotted-key objects or a CSV table.
Open tool →Strip ANSI escape codes from logs or render them as colors.
Open tool →Rewrite mixed log timestamp formats to ISO 8601 UTC and sort them.
Open tool →Percentiles, queueing math, rate limits and telemetry volume: the numbers behind a capacity plan.
Compute p50 to p99.9 latency percentiles from a list of values.
Open tool →Solve concurrency = throughput × latency to size pools and workers.
Open tool →Simulate token-bucket rate limiting against steady or bursty traffic.
Open tool →Convert between requests per second, minute, day and month.
Open tool →Estimate time-series cardinality, memory and storage for a metric.
Open tool →Balance tracing cost against coverage and pick a sample rate.
Open tool →Build requests, look up status codes and encode URLs without leaving the tab.
Build curl commands from a form, with correct shell escaping.
Open tool →Search HTTP status codes with their causes and what to do.
Open tool →Percent-encode or decode text and break a URL into its parameters.
Open tool →Send GET, POST, PUT, PATCH and DELETE requests and inspect the response.
Open tool →Open a .har file and see requests, sizes and timings on a waterfall.
Open tool →Redact cookies, auth headers, tokens and passwords from a HAR file.
Open tool →Look up MIME types by extension and detect a file's real type from its bytes.
Open tool → soonSee the HTTP headers a server sends back for any address.
soonMeasure how well your CDN delivers your site to visitors in different regions.
soonMeasure how fast a page loads and see where the time goes.
soonSee how fast your page loads on a phone, where most visitors are.
soonTest the performance of a website from start to finish, on demand.
Sanity-check pod resources, generate probe YAML and plan DNS changes before you apply them.
Encode, decode, hash, generate and compare — locally, so secrets never leave your machine.
Convert text to and from Base64, UTF-8 safe.
Open tool →Decode a JSON Web Token and inspect its claims — locally.
Open tool →Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes and HMACs.
Open tool →Generate v4 and v7 UUIDs in bulk and decode existing ones.
Open tool →Compare two text blocks and see the differences line by line.
Open tool →Escape text as HTML entities or decode &, and — back.
Open tool →Escape text as a JS or JSON string literal, or unescape \n, \" and \u sequences.
Open tool →Generate fake JSON test data from a template with placeholders.
Open tool →Turn one data format into another: JSON, XML, YAML, CSV and INI, classes generated from JSON, SQL to MongoDB, images to data URIs.
Convert JSON to clean, correctly quoted YAML.
Open tool →Convert YAML to JSON and see how your file is really parsed.
Open tool →Convert JSON to well-formed, indented XML.
Open tool →Convert XML to JSON, keeping attributes and repeated elements.
Open tool →Convert XML documents and config files to readable YAML.
Open tool →Generate an XSD schema from a sample XML document.
Open tool →Convert CSV or TSV to a JSON array of objects.
Open tool →Convert CSV rows to well-formed XML elements.
Open tool →Convert CSV rows to a YAML list of mappings.
Open tool →Generate CREATE TABLE and INSERT statements from CSV.
Open tool →Convert INI and .conf configuration files to JSON.
Open tool →Convert INI configuration files to well-formed XML.
Open tool →Convert INI configuration files to YAML.
Open tool →Generate Java POJO classes from a JSON sample.
Open tool →Generate C# classes from a JSON sample.
Open tool →Generate typed PHP classes and DTOs from a JSON sample.
Open tool →Generate a proto3 .proto schema from a JSON sample.
Open tool →Translate SQL statements into MongoDB query syntax.
Open tool →Base64-encode an image into a data URI for HTML and CSS.
Open tool →Decode a data URI or Base64 string into an image file.
Open tool →Convert RGB and RGBA color values to hex codes.
Open tool →Convert hex color codes to RGB, RGBA and HSL.
Open tool →Convert internationalized domains between Unicode and Punycode.
Open tool →Pick a colour and get HEX, RGB, HSL, CMYK codes and a WCAG contrast check.
Open tool →Beautify or minify JSON, CSS and JavaScript in one paste.
Validate and pretty-print JSON, with clear error messages.
Open tool →Validate JSON and compact it into the smallest valid form.
Open tool →Turn minified or messy CSS into clean, indented output.
Open tool →Strip comments and whitespace from CSS and see the savings.
Open tool →Turn minified JavaScript into readable, indented code.
Open tool →Strip comments and extra whitespace from JavaScript.
Open tool →Clean messy HTML: strip Word junk, inline styles, classes and empty tags.
Open tool →Preview SVG code safely, optimize it and export it as PNG.
Open tool →Read cron expressions and convert timestamps between epochs, formats and time zones.