All Online Tools

Calculate age from a birth date and reference date.

Calculate missing width or height while preserving aspect ratio.

Encode text to Base64 or decode Base64 to text.

Encode or decode URL-safe Base64 without padding.

Calculate body mass index from metric height and weight.

Generate valid-format Brazilian CNPJ numbers with check digits.

Validate Brazilian CNPJ numbers using check digits.

Generate valid-format Brazilian CPF numbers with check digits.

Validate Brazilian CPF numbers using check digits.

Calculate break-even units from fixed cost, price, and variable cost.

Inspect an IPv4 or IPv6 CIDR range.

Calculate WCAG contrast ratio between two HEX colors.

Convert colors between HEX and RGB.

Estimate future value with compound interest and optional monthly deposits.

Validate card numbers with the Luhn checksum.

Validate and explain standard five-field cron expressions.

Calculate upcoming run times for a cron expression.

Minify small CSS snippets by removing comments and extra whitespace.

Convert CSV rows to JSON arrays or simple JSON arrays to CSV.

Convert CSV data into a Markdown table.

Convert bytes, KB, MB, and GB using binary 1024-based units.

Add or subtract days from a date.

Calculate the number of days between two dates.

Calculate sale price and savings from an original price and discount rate.

Look up common DNS records through a selected resolver.

Remove repeated lines while keeping the first occurrence.

Extract email addresses from pasted text.

Generate realistic fake data for forms, tests, and demos.

Generate MD5, SHA-1, SHA-256, or SHA-512 hashes.

Generate keyed HMAC signatures with SHA-1, SHA-256, or SHA-512.

Escape HTML entities or convert entities back to text.

Look up the standard phrase and class for an HTTP status code.

Validate International Bank Account Numbers with the MOD 97 check.

Generate format-level sample mobile phone numbers for several countries.

Validate IPv4 and IPv6 addresses and inspect basic address properties.

Convert IPv4 addresses to integers or integers back to IPv4.

Run jq-style queries against JSON input.

Format or compact JSON with validation.

Convert JSONL records to a JSON array or a JSON array to JSONL.

Validate JSON against a JSON Schema document.

Decode JWT header and payload without verifying the signature.

Sort lines in ascending or descending order.

Shuffle lines into a random order.

Estimate monthly loan payments from principal, annual rate, and term.

Generate placeholder paragraphs for layouts and content tests.

Calculate gross profit, margin, and markup from cost and selling price.

Convert Markdown to sanitized HTML with a rendered preview.

Generate HTML meta tags for title, description, canonical URL, and Open Graph.

Look up MIME types from file extensions or extensions from MIME types.

Convert numbers between decimal, binary, hexadecimal, and octal.

Generate and preview Open Graph metadata.

Generate random passwords with several length presets.

Calculate percentages, percentage increase, and percentage decrease.

Parse international phone numbers with libphonenumber metadata.

Generate a copyable SVG QR code from text or a URL.

Parse URL query strings into JSON.

Generate random integers in a selected range.

Generate random alphanumeric strings.

Escape text for safe use inside a regular expression.

Test a Go regular expression against sample text.

Generate a simple robots.txt file with sitemap support.

Calculate tax amount and final price.

Check title and meta description length for search snippets.

Preview a search result title, URL, and description.

Generate a simple XML sitemap from a list of URLs.

Generate SEO-friendly slugs with multilingual transliteration.

Format compact SQL into a readable keyword-based layout.

Convert IPv4 CIDR prefix lengths and subnet masks.

Convert text between lowercase, uppercase, title case, sentence case, snake case, kebab case, camel case, and Pascal case.

Compare two text blocks line by line.

Reverse characters, words, or line order.

Convert a date and time from one IANA time zone to another.

Calculate tip, total bill, and per-person split.

Generate time-based one-time password codes from a Base32 secret.

Convert common length, weight, and temperature units.

Convert Unix timestamps to UTC dates or UTC dates to Unix timestamps.

Encode or decode URL query text.

Extract HTTP and HTTPS URLs from pasted text.

Break a URL into scheme, host, path, query, and fragment.

Parse browser, operating system, device, and bot hints from a user agent string.

Generate one or more UUID v4 values.

Validate whether a value is a correctly formatted UUID.

Trim text, collapse extra spaces, or remove blank lines.

Count words, characters, lines, and bytes.

Count weekdays between two dates while excluding Saturdays and Sundays.

Format compact XML into readable indented XML.

Convert YAML to JSON or JSON to YAML.