Front-end developer and tech writer · View profile
· 16 min read
01/02/2026 is 1 February in most of Europe and 2 January in the United States, and nothing in the string says which. ISO 8601 fixes that, sorts as text, and stops being ISO 8601 in four specific places that RFC 3339 rejects.
· 13 min read
How to tell a sound secret-key generator from an unsound one, using this one as a worked example: which random source it calls, how to compute the entropy yourself, and what actually breaks the day you rotate the key.
· 15 min read
Numbering starts at 1 and cannot be set to 0, the alignment is spaces rather than zeros, and the remover undoes eight of the eleven separators without touching the indentation. What it still cannot do is tell your numbers from its own.
· 12 min read
Three encodings, one visible difference: %20 or +. The builder's form mode matches URLSearchParams byte for byte on seventeen values — but give it a base URL with a fragment and every parameter lands inside the hash, where no server sees it.
· 15 min read
A PDF stores glyphs at coordinates — not lines, not paragraphs, not a reading order. Extraction rebuilds the text from those positions, which is why two columns come out interleaved, a table loses its cells, and a scan gives you nothing at all. Measured by running the tool.
· 14 min read
Scaling until the loudest sample hits a ceiling barely changes how loud something sounds. Measuring in LUFS does. This tool measures — in two passes, correctly — and then prints a result it never verified, which on ordinary material can be well over a decibel adrift.
· 11 min read
One ffmpeg command, no encoder, and a result whose video stream is byte-for-byte the one you started with — verified by checksum. Plus why the file barely shrinks, and the difference between a silent track and no track at all.
· 14 min read
Four real stylesheets run through the minifier, measured raw and after gzip. Stripping every space saved 48, 103, 104 and 147 compressed bytes; stripping comments saved 57, 1 358, 2 420 and 1 042. Plus the five inputs this minifier breaks.
· 13 min read
One emoji is 1 character, or 7, or 11, or 25, depending on who is counting. Which one your form, your database and your SMS gateway mean — and a one-paste test that tells you which you are facing.
· 14 min read
A URL at the end of a sentence keeps the full stop; an email address at the end of the same sentence does not. An accented first name in an address comes back truncated. Every case here was run through the tools and the exact output is reported.
· 12 min read
Three commands hide behind three buttons: one frame at a timestamp, a fixed number spread across the clip, or one every N seconds. Here are the exact arguments, the 60-frame ceiling and the reason a frame from the middle of a compressed clip can never be as sharp as a keyframe.
· 11 min read
There are two completely different ways to turn a video, and only one of them touches the picture. This tool takes the slow, lossy, universal road — and there is a good chance your sideways phone clip does not need it at all.
· 13 min read
English title case has three different cutoffs depending on the style guide. French, Spanish, Portuguese and Italian have none at all. German capitalises every noun. The tool knows about none of this — here is exactly what it does.
· 11 min read
This is grep for people who do not use grep, with one important difference: the match is a plain substring, so a real regular expression returns an empty box and no error. Every claim here was checked by running the tool.
· 11 min read
Two lines that look identical are often not identical. Case, a trailing space, a no-break space and two different encodings of the same accented letter were each run through the duplicate finder, and it reported no duplicates for three of the four.
· 12 min read
A paste carries characters you cannot see: no-break spaces, soft hyphens, zero-width spaces, tabs and CRLF. Four cleanup tools were run against each of them, and they use three different definitions of whitespace.
· 12 min read
The encryption is the easy half. Here is exactly what the browser tool does to your file — cipher, key derivation, salt, nonce — and why an encrypted attachment with the passphrase in the same thread protects nothing at all.
· 16 min read
Swapping names for identifiers does not take a database out of the GDPR — Article 4(5) and Recital 26 say so directly. Genuinely synthetic data is outside the Regulation altogether. That single distinction decides how you seed a staging environment.
· 15 min read
Cue 12 of the English track is not cue 12 of the French one, because translators split and join sentences differently. Two strategies exist for pairing them; this merger uses neither — it interleaves. Here is what that gives you and when it is good enough.
· 15 min read
Measure the offset at two points instead of guessing it once. If it is constant, one shift fixes the file. If it grows, it is a frame-rate mismatch — 25 fps against 23.976 drifts 2.5625 seconds every minute — and no shift will ever fix that.
· 13 min read
Removing the numbers and the timestamps is the easy half. The half that decides whether the transcript is readable is the italic tags, the dialogue dashes, the sound descriptions and the sentences broken across two cues — and this converter leaves every one of them for you.
· 12 min read
A comma is quoted, a quotation mark is doubled, and a two-line cue keeps both lines — verified byte-identical over three consecutive round trips. What can still change your file is the spreadsheet in the middle.
· 15 min read
Luhn is a checksum for catching typos, patented in 1960, and that is its entire job. A number that passes it tells you nothing about any account. For testing a payment integration you need your processor's published numbers, not a generated one.
· 18 min read
Whether a drawn signature is valid is settled elsewhere. What decides whether your document actually gets signed is the order you ask people in, what the audit trail records, and six failure modes that have nothing to do with the law.