Developer tools
JSON, encoding, regular expressions, color contrast
12 tools
- JSON Formatter & ValidatorValidate JSON and see the exact line and column of any syntax error. Pretty-print with 2 or 4 spaces or tabs, minify, sort keys, then copy or download.
- CSV ⇄ JSON ConverterConvert CSV or TSV to JSON and JSON back to CSV or TSV. Handles quoted fields, line breaks in cells, UTF-8 BOM, delimiter detection and Shift_JIS, and lets you pick, reorder and rename columns.
- YAML ⇄ JSON ConverterConvert YAML to JSON and JSON to YAML safely: custom or executable tags are never loaded, alias expansion is limited, and errors show the line and column.
- Base64 Encoder & Decoder (Text and Files)Encode text (including emoji and any language) to Base64 as UTF-8 and decode it back. Supports URL-safe Base64, optional padding, files and data URLs.
- URL Encoder & Decoder (Percent-Encoding)Percent-encode or decode URLs and query strings in any language with encodeURIComponent, encodeURI or form encoding (+). Broken % sequences show the exact error position.
- Regex Tester (JavaScript)Test JavaScript regular expressions with highlighted matches, numbered and named groups and a replace preview. Patterns that run too long (ReDoS) are stopped automatically.
- Unix Timestamp ConverterConvert Unix timestamps to dates and dates to timestamps. Seconds, milliseconds, microseconds or nanoseconds, ISO 8601 with IANA time zones, values past 2038 and negative values before 1970.
- IPv4 CIDR Calculator (subnet, network and broadcast)Calculate the network address, broadcast address, usable host range, subnet mask, wildcard mask and address count from an IPv4 address and prefix length, including /31 and /32.
- Cron Expression Explainer & Next Run Times (Standard cron / Cloudflare)Explains each of the five cron fields in plain English and lists the next run times, keeping standard cron (server time zone) and Cloudflare Workers Cron Triggers (UTC) apart.
- Color Contrast Checker (WCAG 2.2 AA and AAA)Enter text and background HEX colors to get the WCAG 2.2 contrast ratio and see whether normal text, large text and UI components meet AA and AAA.
- HTTP Status Codes Reference & Search (IANA Registry)Search HTTP status codes by number or keyword and see the official IANA name, the defining RFC and a plain-language explanation. Unassigned codes are shown as unassigned, never guessed.
- CSS Gradient Generator (linear and radial)Edit the color stops and angle of a linear or radial gradient, watch the live preview and copy the CSS background code.
More tools are being released step by step.