Case StudyPrivacy / SSG / i18n / JavaScript

FormattedAI.pl

Free, privacy-first web tools for developers and content creators. 14 tools running in the browser, from an AI-tell text scanner with a local LLM to AVIF conversion, OCR and PDF utilities. Vanilla JS, open source, no accounts, no tracking.

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Preview of the FormattedAI.pl project

The Problem

Most online formatting and conversion tools upload your files to someone else's server. For developers working under NDA that is a contract breach waiting to happen, and for everyone else it means cookie banners, trackers and accounts for a task that should take seconds.

The Solution

FormattedAI is a suite of 14 free tools where privacy comes from architecture, not from a policy page: the site is static, has no accounts and no analytics, and the work happens in the browser through WebAssembly and Web Workers.

  • Text -- Text Humanizer, Markdown Formatter, JS and CSS minifiers, a JSON Formatter with tree view, diff and JSONPath, and a Regex Tester with a ReDoS watchdog
  • Images -- AVIF and HEIC converters (WebAssembly), OCR in 100+ languages (Tesseract.js), and a color palette generator with WCAG contrast checks
  • Documents -- PDF merge, split and compress, HTML to PDF, and an email-safe signature generator
  • SEO & GEO -- a tag generator covering meta tags, Open Graph, Twitter Cards, Schema.org JSON-LD, llms.txt and robots.txt

Flagship: Text Humanizer

Instead of blindly rewriting text, the Humanizer scans it for AI tells -- buzzwords, hedge openers, cliche closers, em-dash overuse -- and proposes a fix for each finding that you accept or dismiss, with sentence rhythm shown as a signal rather than a verdict. An opt-in deep mode runs a Qwen 2.5 model directly in the browser via WebLLM, so even LLM-assisted analysis never sends your text anywhere.

Technical Decisions

The whole site is vanilla HTML, CSS and JavaScript: Sass compiles one stylesheet per tool, esbuild bundles the scripts, and client-side libraries (jSquash for AVIF, Tesseract.js, PDF.js with pdf-lib, Terser, CSSO, WebLLM) are vendored into the repo. No framework, no runtime dependencies.

Two tools genuinely need a server -- HTML-to-PDF rendering through headless Chromium and metadata fetching for the SEO generator -- and run as small hardened Node services with SSRF guards that validate after DNS resolution, private-IP blocking and layered rate limits. Everything else runs fully client-side.

The May 2026 "Hybrid Console" redesign rebuilt every page around a dark-first design system with a tool catalog, a command palette and a complete Polish/English mirror. Deployment is GitHub Actions with rsync to a VPS behind nginx.

The content layer: Dziennik

Tools pull traffic from task-shaped queries, but they do not explain why anyone should trust them. Hence Dziennik, the project journal - guides written around the tools rather than next to them: how AI detectors actually measure burstiness and perplexity, why Markdown from ChatGPT falls apart in Google Docs, when AVIF is worth the switch, what optimising for AI search engines involves, and how far you can get with a PDF without uploading it anywhere.

Every entry carries a category, a reading time and a path into the tool it describes. The journal has its own RSS feed, and the "About" page adds an FAQ in structured data - both so the writing can be cited by classic search engines and by models alike.

Results

  • 14 tools live -- five of them shipped in one August week, three in a single day
  • 12 of 14 tools run entirely in the browser; files never leave the machine
  • Open source (MIT) with automated CI deployment
  • A journal with an RSS feed: tool-linked guides written to be cited by AI search engines
  • Built to be cited by AI search engines: llms.txt, structured data and full AI-crawler access
FormattedAI homepage after the Hybrid Console redesign, dark theme with tool categories

Homepage

The Hybrid Console redesign: dark-first design system, four tool categories and a full Polish/English mirror.

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