Tools and reference sheets
tallge is a set of small tools that run entirely in your browser, and reference pages for the things developers and administrators look up repeatedly.
Tools
- JSON formatter
- Format, validate, minify and sort keys, with errors reported by line and column.
- Base64
- Encode and decode Base64 and Base64url as UTF-8, with clear errors for bad input.
- JWT decoder
- Decode a JSON Web Token, read its claims and dates, and check an HMAC signature.
- URL encoder
- Percent-encode with encodeURIComponent or encodeURI, decode, and split a URL into its parts.
- Time converter
- Unix seconds or milliseconds and ISO 8601, in UTC or any IANA time zone.
- Password generator
- Random passwords from crypto.getRandomValues, without modulo bias, with an honest entropy figure.
- UUID v4
- Random version 4 UUIDs in bulk, plus a checker that reads the version and variant.
- Hashes
- SHA-1, SHA-256, SHA-384 and SHA-512 of text or a file, in hex or Base64.
- Subnet calculator
- IPv4 and IPv6 prefixes: network, mask, wildcard, first and last host, size, and a bit diagram.
- Regex tester
- Test JavaScript regular expressions with flags, groups, highlighted matches and a replace preview.
- Cron explainer
- Read a five-field cron expression in plain English and see the next five runs.
- Colour converter
- Convert hex, rgb() and hsl() and check WCAG contrast between two colours.
- Text utilities
- Sort and deduplicate lines, count characters, words and bytes, and convert case.
- Diff checker
- Compare two texts line by line and get the differences as a unified diff.
- Semver range checker
- Test versions against an npm-style range such as ^1.2.3 or >=2.0.0-beta <3, and see what the range really means.
- Unicode inspector
- Show every code point in a text with its UTF-8 and UTF-16 form, and find invisible characters, odd spaces and mixed scripts.
- Number bases and floats
- Convert integers between decimal, hex, octal and binary with two’s complement and byte order; inspect IEEE 754 floats bit by bit.
Reference
- Git by task
- Everyday git commands grouped by what you are trying to do, including how to undo things.
- Regular expression syntax
- JavaScript regex syntax: classes, anchors, quantifiers, groups, lookaround, flags and replacement tokens.
- Cron syntax
- The five crontab fields, special characters, shortcuts, and the mistakes that make jobs silently not run.
- HTTP status codes
- The status codes you actually meet, with the situations that produce them.
- HTTP headers
- Common request and response headers: caching, content, ranges, cookies, CORS and security headers.
- Linux commands by task
- Shell commands for files, text, processes, disks and basic network diagnostics, grouped by task.
- Signals and exit codes
- Unix signals with their numbers and default actions, shell exit codes such as 126, 127 and 137, and how services are stopped.
- File permissions (chmod)
- Unix permission bits in octal and symbolic form, common modes, special bits and umask.
- CIDR and subnet sizes
- IPv4 prefix sizes and masks, private and special ranges, and the IPv6 prefixes in common use.
- Date and time formats
- ISO 8601, RFC 3339, Unix time and HTTP dates, with the parsing traps in JavaScript and SQL.
Downloads
- Printable reference sheets
- Every reference page as a PDF for offline use or printing, with file sizes and SHA-256 checksums.