Guides
Practical explainers that pair with Everyday Kit tools—passwords, JSON, timestamps, PDFs, and more. Written for humans and clear enough for answer engines to cite.
How to create a strong password (and store it safely)
Length beats complexity theater. Learn what makes a password strong, how browser generators help, and why a password manager matters.
What is Base64 encoding? (and when not to use it)
Base64 turns binary or awkward text into ASCII-safe strings for APIs and data URIs. It is encoding—not encryption.
How to format and validate JSON before you ship it
Beautify JSON for reading, minify it for transport, and catch trailing commas or quote mistakes early.
Unix timestamps explained: seconds, milliseconds, and time zones
Learn what Unix time is, how to tell seconds from milliseconds, and how to convert timestamps when debugging APIs and JWTs.
Convert cURL to JavaScript fetch (safely)
Turn API docs and DevTools cURL snippets into fetch() code. Know which flags translate cleanly and what to fix afterward.
Merge PDFs in your browser without uploading files
Combine invoices, scans, or application packets locally. Why client-side merging helps privacy—and what to check before you send.
JWT decode vs verify: what a browser decoder is for
Decoding a JWT shows header and payload claims. Verification proves the signature—and must happen on a trusted server.
How to split a restaurant bill with tip
Even splits, tip percentages by custom, and per-person totals—plus why country presets are only a starting point.
What is a URL slug? (and how to write a good one)
Slugs are the readable part of a URL after the domain. Keep them short, lowercase, hyphenated, and stable.
Verify a download with SHA-256 checksums
Compare a publisher’s hash with a local SHA-256 digest to check integrity after you download a file.
Compress and resize images for faster pages
Shrink dimensions and quality before upload to improve load time—without sending photos to a random server.
HTML entities and escaping: keep markup from breaking
Learn when to turn <, >, and & into entities so user text does not become accidental HTML.
HEIC vs JPG: why iPhone photos will not open, and how to convert them
HEIC is the format iPhones use by default. Learn why other devices refuse it, how to convert HEIC to JPG without uploading photos, and how to make your iPhone shoot JPG.
How to fix out-of-sync subtitles (SRT and VTT)
Subtitles ahead of or behind the audio? Learn how to tell a fixed offset from frame-rate drift, and how to shift SRT/VTT timestamps in your browser.
What does charging an EV actually cost?
The formula behind EV charging cost: battery size × charge percentage × electricity price, plus the charging losses most estimates forget.
How word counters actually count words (and why tools disagree)
Why Word, Google Docs, and browser counters can disagree, what counts as a word, and how to hit a limit without uploading your draft.
How to read a cron expression without guessing
The five cron fields in order, why Sunday can be 0 or 7, and how to turn 0 9 * * 1-5 into “9:00 on weekdays.”
How to calculate age in years, months, and days
Why “divide days by 365” is wrong, how leftover months work, and what happens to a 29 February birthday.
Merge or split a PDF without uploading it
Why most “free PDF” sites upload your documents, and how to combine or extract pages locally in the browser.
How to turn a JSON array into a CSV for Excel
Map object keys to columns, quote commas correctly, and keep nested objects without losing data — then open the file in Excel or Sheets.
Title Case vs sentence case (and when to use each)
What each style capitalizes, why automatic Title Case is not AP or Chicago, and a one-click way to convert text in the browser.