Zellio.io

Changelog

Last updated: September 2026

What has shipped, month by month. Every entry here corresponds to real, deployed work — if a month is quiet, it says so by being absent rather than by being padded.

September 2026

  • Carousel Maker (/tools/generators/carousel-maker): turn a post you have already written into a swipeable deck — a PDF for LinkedIn or a folder of PNGs for Instagram. A line of dashes starts the next slide, a hash makes a heading, an angle bracket pulls a quote out and a fenced block becomes a code slide with its indentation intact. The slides are drawn on a canvas in your own tab, which is why there is no watermark and no export limit, and why the preview is the file rather than a picture of it.
  • PDF to Word (/tools/generators/pdf-to-word): convert a PDF into an editable .docx without uploading it. It rebuilds the document rather than dumping the text — paragraphs joined back together, headings as headings, lists as lists, ruled tables as real tables, and charts, diagrams and photographs cropped out and placed as pictures with their captions. Before you download anything it shows what it understood, and it says plainly when a PDF is a scan and has no text to convert at all.
  • Sensitive Data Scanner: a third way to redact, for the moment before you paste something into an AI assistant. Every email, number, key and name you list becomes a stand-in of the same kind — one per value, reused wherever it appears, so the assistant can still tell two customers apart — and the reply comes back through a Restore box with the real values in place. The mapping between the two stays in your tab and never enters a link or a file you did not ask for, and the page is plain that this is pseudonymisation, not anonymisation.
  • Invoice Generator: four templates to choose from — Classic, Modern, Minimal and Elegant — each with an accent colour, and your logo on the invoice. Uploaded logos have their empty margins trimmed and are scaled to fit without stretching, and a live preview beside the form is drawn from the same layout as the PDF, so what you pick is what downloads.
  • Time-Locked Message (/tools/text/time-locked-message): write a message, pick a date, and seal it so nobody, including you, can read it before then. It uses drand's timelock encryption: sealing happens on your device without contacting anyone, and opening fetches one public signature that did not exist until the moment you chose. Share it as a link with a countdown, or as sealed text that drand's own tools also open.
  • HTML & CSS Playground: three panels and a live preview, with a console that captures what the snippet logs and the errors it throws. The preview runs in a sandboxed frame with no origin, so nothing inside it can reach this page or your saved work — and code that arrives in a link is listed, explained and left un-run until you press the button.
  • Encryption Algorithm Simulator: AES-128 round by round with the state grid after every operation, SHA-256 across all sixty-four rounds with its working variables, and RSA and Diffie-Hellman on numbers small enough to check by hand. The substitution table and the hash constants are derived from their definitions rather than copied, and the published test vectors are asserted in the test suite. Educational only, and the page says so.
  • Network Protocol Simulator: step through a recursive DNS lookup, the TCP handshake and close, the TLS handshake in either version, and the full request lifecycle the three add up to — each packet laid out field by field, on a timeline you can change by typing a different round-trip time. A simulation: no packets leave your machine, and the page says so.
  • OAuth Flow Simulator: step through the authorisation code flow with and without PKCE, client credentials, the device flow and refresh, seeing every request and response as wire text. The access and ID tokens are real JWTs signed in your tab with a throwaway key, so they open in the decoder, pass the five checks an API performs, and fail the signature check the moment you change a character.
  • Image Resizer: resize up to fifty images in one pass and download them as a ZIP, with each file's current and resulting size shown before you run it. Seven ways to say what you want — fit inside, fill and crop, exact, percentage, width, height or longest edge — sixteen ready-made platform sizes, and a box to save your own sizes on this device and reapply them with one click.
  • Labs (/labs): Regex Golf (28 holes scored against par), Cron Puzzles (28 schedules checked by their firings, not their text) and Data Wrangling in SQL (31 puzzles run on DuckDB and compared cell by cell). Every reference answer executes in the test suite; progress, best scores and a day streak stay in your browser; a solve shares as a link that names the puzzle and the score, nothing else.
  • Workflow builder (/workflows): chain any of the headless text operations from the tools, set their options, run the chain on a paste with every intermediate shown, and keep it — saved on this device, copied as a link, or exported as JSON for someone else to import. Passwords never enter a link or a file; the text you run on never leaves the tab.
  • Projects (/projects): a device-local container per job — files, saved tool states, bookmarks, recipes and notes — kept in your browser's storage and exported as one bundle, optionally AES-GCM password-protected. Import merges a bundle into a project or creates one from it. No sync, no server; Safari's seven-day eviction is stated on the page.
  • Recipes (/recipes): thirteen multi-step jobs, each on its own page. Eleven run on the page — paste once, press Run, read every intermediate result and open any step in its tool; two walk through image and document tools in order with the file handed on. The share link carries your input, never a file.
  • Batch Workspace: drop up to fifty files, pick one operation — resize, convert, compress, strip metadata, hash, normalise text, rename by pattern or inspect PDFs — and download one ZIP or one report. Files the operation does not apply to are skipped and say so; the share link carries the settings, never the files.
  • Data Lab: the SQL playground now profiles every column on load (type, range, distinct count, missing share), lists quality findings — duplicate rows, missing values, constant columns, numbers stored as text — each with the query that shows the rows, completes column names and keywords as you type, exports results as JSON as well as CSV, and saves or shares queries through the same Save / Copy link bar as every other tool.
  • Sensitive Data Scanner: find emails, phone numbers, card numbers, IBANs, IPs, coordinates, keys and tokens in text or logs — verified by checksum where a checksum exists — and copy or download a redacted version. Found by shape, never by meaning, and the page says so.
  • UI Sound Generator: design clicks, pops, chimes and error buzzes with eight controls, hear them on a click, and download the WAV or copy Web Audio code that recreates the sound. Synthesised as plain samples in the page, so the preview and the file are identical.
  • Inspect anything (/inspect, and a drop strip on the homepage): paste text or drop a file and be told what it is — JSON, a token, a cron expression, an error, an image, a PDF — with the right tool opened and, for nine file tools, the file already loaded.
  • Three SVG tools: a seeded Blob & Wave generator (SVG, React or CSS background), a Pattern generator for repeating CSS backgrounds, and an SVG Optimizer that runs SVGO in the browser with before/after and gzipped sizes and a React-component export.
  • Image Vectorizer: trace a PNG, JPEG or WebP into a scalable SVG on your device. VTracer runs as WebAssembly in a background thread, with presets for black-and-white marks, flat-colour logos and photos, and sliders for speckle, colours, corners and curve simplification.
  • Four new tools: a Palette Extractor with a full contrast matrix (WCAG and APCA), a CSS Theme Generator that turns one brand colour into light and dark themes with OKLCH ramps, and Flexbox and CSS Grid playgrounds that write the CSS and Tailwind for the layout you build by clicking.
  • Save your work: every text tool now has Save, Copy link, Duplicate and Reset. Saved work lives on this device (in IndexedDB, not on a server) and reopens from your shelf; Ctrl+S saves, ? lists the shortcuts.
  • A privacy receipt after each copy or download lists every request the page made while you worked, from the browser's own record — on a clean run, none carried your data.
  • The command palette (Ctrl+K) now understands jobs: type “cron every weekday at 9”, paste a token or a colour, and it opens the right tool with it loaded. It also finds guides and shows your recent and saved work when empty.
  • The regex tester warns about patterns likely to backtrack catastrophically before they run; the QR reader lists what to check in a decoded link — shorteners, look-alike domains, a username before the @; the cron builder explains each field as you type; the JWT decoder explains every claim.
  • Zellio can be installed as an app on Chrome and Edge, and the shelf explains the Add-to-Home-Screen route on iOS.
  • Launched the Library: 191 hand-checked entries across four collections — regex, cron and SQL patterns; fill-in-the-blank AI prompts; email and document templates; and printable cheat sheets. Copy any entry in one click, and every pattern explains why it's written that way and where it deliberately stops working.
  • Patterns open straight into the matching tool — the regex tester or cron builder loads preloaded via the same private link mechanism as the share buttons, so you can test against your own data without anything leaving your browser.
  • Prompts and templates assemble on the page: fill in the blanks, watch the result update live, copy the finished text. Nothing you type is stored or sent anywhere.
  • Tool pages now list the ready-made Library entries that open them preloaded, so the pattern you were about to write by hand is one click away.
  • Published a new guide on how to structure an AI prompt — the five-part anatomy behind every prompt in the Library, what frameworks like RICECO and TCF actually buy you, and a step-by-step for writing your own.
  • Added your Shelf: bookmark any pattern, prompt, template, cheat sheet or tool and it's saved on your device — never uploaded, and readable offline.
  • The Library grew two collections: Snippets (copy-paste JavaScript, Python, bash and CSS, each verified by actually running it) and Formulas (Excel & Sheets formulas assembled from your own cell references).
  • Four more Library collections: Commands (CLI recipes explained flag by flag), Errors (what a message actually means and how to clear it), Comparisons (X versus Y, decided rather than hedged) and Checklists (tickable and printable, with your ticks kept on your device).
  • Corrected a batch of factual errors found by an audit of the whole Library, each verified by running the thing rather than re-reading it. The one worth naming: a suggested command for freeing a busy port matched client connections as well as the listening socket, so following it could have force-killed the reader's own browser. Also corrected advice that would have deleted a lockfile, a Python flag that has done nothing since Python 2, several regex edge cases that claimed to match text they did not, an Excel formula described with its arguments in the wrong order, and a body-size limit quoted ten times too high.
  • Library entries began gaining a part-by-part breakdown of the pattern or command, the mistakes people actually make with it, and answers to the questions it raises — replacing a short explanation with something you can learn the thing from.

August 2026

  • Substantially expanded the written guidance on every tool page: practical tips, real use cases, honest comparisons with alternatives, and the mistakes each tool exists to prevent.
  • Added shareable links on the regex tester, cron builder, subnet calculator and diff checker — copy a link that reopens the tool with your exact input, stored in the link itself rather than on any server.
  • Added “Send to” chaining: hand a tool's output straight to another tool, such as Base64 output into the hash generator, without copying and pasting.
  • Rebuilt the guides into full articles with tables, worked examples and step-by-step procedures, and added a tenth guide on querying large CSV files with SQL.
  • Widened guide and information pages to match the rest of the site, with a table of contents that follows you as you read.
  • Removed the footer visit counter, which reset on every deployment and understated the truth. A counter that miscounts is worse than none.
  • Fixed the header navigation overflowing on tablet-width screens.

July 2026

  • Added the Document Privacy Inspector: see what a PDF or Office file carries beyond its visible content — author names, tracked changes, cropped-away image regions — and save a clean copy, with a re-scan proving what was removed and an honest report of what a clean copy cannot remove.
  • Added opt-in face detection to the Image Redactor. The model runs entirely in your browser; the weights are served from our own origin and nothing is sent anywhere.
  • Image Compressor gained batch mode: up to twenty images against one target size, with per-file results and a download-all.
  • The Hash Generator can now hash files as well as text, for checking downloads against published checksums.
  • Published three in-depth guides: why in-browser tools are more private than uploads, choosing an image format, and character encoding explained.

June 2026

  • Launched with the core tool set across seven categories: developer utilities, text tools, image tools, generators, measurement and conversion, network tools, and the WebAssembly-powered CSV & SQL playground.
  • Every tool runs entirely client-side from day one — no accounts, no uploads, no processing servers.
  • Published the first six guides and the site's legal and transparency pages.