Web & encoding · 5 min read
Base64 decode and encode: for transport, not security
Base64 decode and encode in the browser — the 4/3 size rule, padding, the base64url variant and the Unicode bug that makes decoded text look like garbage.
Blog
One practical guide for every tool
19 posts, one per tool — each covering the format behind the tool, the specific mistakes worth avoiding, and when a different approach is the better answer. Every post links straight to the tool it supports, so you can read the reasoning and then use it in the same sitting.
All posts
Data converters · 5 min read
CSV to JSON: from a spreadsheet to structured data
Convert CSV to JSON in the browser — header rows, delimiters, quoting rules and type handling explained, with the spreadsheet exports that break parsers.
Web & encoding · 5 min read
cURL to fetch: moving a request from terminal to browser
cURL to fetch conversion for JavaScript: headers, bodies, auth and methods mapped correctly, plus the CORS reality that decides whether a request works.
Data converters · 6 min read
Excel to JSON: turning workbooks into structured data
Convert Excel to JSON in the browser from XLSX workbooks — headers, date serials, formulas and multiple sheets explained, with nothing uploaded.
JSON tools · 6 min read
JSON diff: comparing data the way it is actually structured
Compare two JSON payloads with a structural JSON diff that ignores key order and whitespace, highlights moved values, and shows why text diffs mislead.
JSON tools · 6 min read
JSON formatter: pretty, minified, and actually valid
A JSON formatter that pretty-prints, minifies and validates with exact error locations — plus the five syntax mistakes behind almost every invalid JSON error.
Data converters · 5 min read
JSON to CSV: flattening nested data without losing meaning
Convert JSON to CSV with nested objects flattened into columns, consistent headers and Excel-safe quoting — and know which shapes should not be flattened at all.
Code generators · 5 min read
JSON to Go: structs that unmarshal on the first try
Convert JSON to Go structs with correct field names and json tags, nested types included — plus the numeric, null and time traps to watch.
JSON tools · 6 min read
JSON to JSON Schema: from sample payload to contract
Convert JSON to JSON Schema in the browser: infer a draft from a real payload, then harden required fields, formats and enums — plus the limits of inference.
Code generators · 5 min read
JSON to SQL: from a payload to a table you can query
Convert JSON to SQL with CREATE TABLE and INSERT statements generated from a real payload, with sensible type mapping, escaping and honest limits.
Code generators · 6 min read
JSON to TypeScript: types that match reality
Convert JSON to TypeScript interfaces from a real API response — optional keys, null unions, nested types — and keep generated types from drifting.
YAML tools · 5 min read
JSON to YAML: making machine output readable again
Convert JSON to YAML in the browser with indentation and quoting controls — and learn the quoting traps that turn a clean config into a broken one.
Web & encoding · 6 min read
JWT decoder: what is inside a token, and what is not
Use a JWT decoder to inspect a token’s header, payload and expiry — and understand why decoding is not verifying, with the claim checks behind most 401s.
Web & encoding · 5 min read
Markdown tables: generate them instead of counting pipes
Build GitHub-flavoured markdown tables from rows or spreadsheets — alignment, escaping pipes, and when a table is the wrong choice for your README.
Data converters · 5 min read
SRT to VTT: subtitles the browser will actually load
Convert SRT to VTT for HTML5 video players — timecode format, styling and cue settings explained, with the accessibility notes that matter.
Web & encoding · 5 min read
Timestamp converter: epoch time without the guesswork
A Unix timestamp converter that works both ways — seconds versus milliseconds, UTC versus local time, and the 2038 boundary that still breaks long-lived systems.
Web & encoding · 5 min read
URL encoding: when to escape, and when you are breaking things
URL encode and decode correctly — reserved characters, plus versus %20, encodeURI versus encodeURIComponent, and the double-encoding bugs behind broken links.
Data converters · 6 min read
XML to JSON: the decisions every converter has to make
Convert XML to JSON with attributes, repeated elements and namespaces handled sensibly — and understand why no two XML-to-JSON mappings look alike.
YAML tools · 6 min read
YAML to JSON: converting configs without losing your mind
Convert YAML to JSON in the browser with multi-document support and exact error locations — plus the YAML mistakes that quietly break CI pipelines.