SellstampFree developer tools
Converters for the data formats a store and its integrations pass around (JSON, CSV, YAML, XML, Base64, URL encoding), checksums, a JWT decoder, a regex tester that cannot freeze the page, cron and timestamp helpers, colour and contrast tools, CSS generators, and the small files a website needs: meta tags, robots.txt, a sitemap and tagged campaign links.
What you paste stays in the page. None of these tools sends anything to Sellstamp, which matters for customer exports, configuration and tokens, and none fetches anything from the addresses you type.
Password generator
Cryptographically random, with the entropy shown honestly.UUID generator
Version 4, from the browser's own generator, one or a hundred at a time.JSON formatter
Pretty-print or minify, with the line and column of any error.Open Graph preview
A share card, an X card and a Google snippet, plus the tags to paste.JSON to CSV
JSON arrays to spreadsheet-ready CSV.CSV to JSON
CSV rows to typed JSON objects.JSON to YAML
JSON to YAML 1.2.YAML to JSON
YAML to JSON, with error positions.XML to JSON
XML to JSON, attributes and repeats handled.Base64 encode decode
Text to Base64 and back, UTF-8 safe.URL encode decode
Percent-encoding, and a URL's parameters.Hash generator
Checksums of text or a file.JWT decoder
Read a token's header, claims and expiry.Regex tester
Matches, positions and groups, safely.Cron expression explainer
Cron in plain English, with next runs.Unix timestamp converter
Epoch seconds and dates, both ways.Color converter
HEX, RGB, HSL and OKLCH.Contrast checker
WCAG contrast ratio and pass or fail.CSS gradient generator
Linear, radial or conic, with live CSS.Box shadow generator
Layered shadows, with live CSS.Meta tag generator
Title, description and share tags.Robots.txt generator
Crawler rules and sitemap lines.Sitemap generator
URLs to a valid sitemap.xml.UTM builder
Tagged links for campaign tracking.User agent parser
Browser, system and device from a UA.