Developer & SEO
Converters, calculators, PDFs, images and everyday utilities. Choose a tool, check its processing notice, and get started without an account.
JSON formatter & validator
Validate, pretty-print or minify JSON locally. Invalid data is never sent to a server.
Developer & SEOCSV to JSON converter
Convert CSV headers and records to JSON, supporting quoted delimiters and line breaks.
Developer & SEOJSON to CSV converter
Convert a flat array of objects to CSV. Formula-like strings receive a protective prefix for spreadsheet imports.
Developer & SEOBase64 encoder & decoder
Encode UTF-8 text as Base64 or decode it back to text. Base64 is encoding, not encryption.
Developer & SEOURL encoder & decoder
Percent-encode or decode a URL component, not a complete website address.
Developer & SEOHTML entity encoder & decoder
Escape HTML characters or decode five basic named entities and numeric references.
Developer & SEOUUID v4 generator
Generate up to 100 random version-4 UUIDs with browser cryptographic randomness.
Developer & SEOSecure password generator
Generate local random passwords using unbiased cryptographic selection. Results are not transmitted or stored.
Developer & SEOSHA-256 hash generator
Hash UTF-8 text locally. A plain hash is not encryption or a suitable password-storage scheme.
Developer & SEOJWT payload inspector
Decode JWT headers and payloads locally. Signatures and authenticity are NOT verified. Do not share live tokens.
Developer & SEONumber base converter
Convert integers between bases 2 and 36 using exact arbitrary-size integer arithmetic.
Developer & SEOHEX to RGB & HSL converter
Convert a three- or six-digit hexadecimal colour to RGB and HSL.
Developer & SEOUTM campaign URL builder
Add campaign parameters to an HTTP(S) URL while preserving existing query parameters.
Developer & SEOSEO meta tag generator
Generate escaped title, description, canonical and Open Graph tags. Rankings are not guaranteed.
Developer & SEORobots.txt generator
Generate basic crawl rules and a sitemap reference. Robots.txt does not secure private pages or remove indexed URLs.
Developer & SEOJSON string escaper
Escape plain text as a valid JSON string including quotes, newlines and backslashes.
Developer & SEOXML sitemap generator
Build a sitemap from public URLs you supply, without crawling websites.
Developer & SEOStructured-data generator
Create basic Organization, WebSite or WebApplication JSON-LD without ratings claims.
Developer & SEOBroken-link checker
Check up to 10 same-site links from one public page; no full-site crawl.
Developer & SEO · Server processingRedirect and HTTP-header checker
Inspect up to five public HTTP redirects and response headers.
Developer & SEO · Server processingDNS lookup
Look up common public DNS record types.
Developer & SEO · Server processingEmail DNS checker
Inspect SPF, DMARC and a supplied DKIM selector; not a deliverability guarantee.
Developer & SEO · Server processingRegular-expression tester
Test JavaScript expressions in an isolated worker with an execution timeout.
Developer & SEOSQL formatter
Indent SQL statements without connecting to or executing a database.
Developer & SEO · Server processingJSON ↔ YAML converter
Convert safe JSON/YAML documents with size and alias restrictions.
Developer & SEO · Server processingWebsite speed checker
Request a real PageSpeed Insights report; Google quotas and availability apply.
Developer & SEO · Optional serviceNo matching tools. Try a shorter search or a category.