Lint HTML for missing DOCTYPE, unclosed tags, and unexpected closing tags. Paste your HTML and get instant feedback. Everything runs locally in your browser — nothing is uploaded.
Removes unnecessary whitespace, comments, and optional closing tags from HTML code to reduce file size without altering rendered output.
Convert HTML markup to JSX for React components. Handles class→className, for→htmlFor, event handlers, and more.
Write HTML and see a live preview rendered in a sandboxed iframe. Perfect for prototyping and testing.
Analyzes your writing with real-time word count, sentence count, syllable count, paragraphs, and advanced readability metrics — Flesch-Kincaid Reading Ease, Grade Level, estimated speaking time, and keyword density. Essential for writers, students, and SEO professionals optimizing content for readability.
Add professional headers and footers to every page of your PDF. Supports text, page numbers ({{page}}/{{total}}), dates, and custom alignment. Perfect for reports and official documents.
HTML Linter lets you lint HTML for missing DOCTYPE, unclosed tags, and unexpected closing tags. Paste your HTML and get instant feedback. Everything runs locally in your browser — nothing is uploaded.. It works on any device with a modern web browser.
Lint HTML for missing DOCTYPE, unclosed tags, and unexpected closing tags. Paste your HTML and get instant feedback. Everything runs locally in your browser — nothing is uploaded. It runs entirely in your browser — no software installation or data uploads required.
Direct text entry, file upload, or URL-based input — depending on the tool. Paste or type your content directly into the provided editor area.
Yes. After the initial page load, HTML Linter runs entirely on your device with no internet connection needed. All processing is done locally.
Tools cover JavaScript, CSS, HTML, SQL, Python, JSON, XML, CSV, and more. Check individual tool descriptions for specifics.
No. All code processing — formatting, minification, conversion, hashing — runs locally in your browser.
Yes. Since processing is local, performance depends on your device. Most operations handle large files without issue.
Yes. SQL uses sql-formatter, JSON uses native JSON.parse, and other formatters follow widely adopted formatting rules.
Yes. All developer tools work fully offline after the initial page load.
Time Converter
Convert between time units including seconds, minutes, hours, days, weeks, months, and years with precise decimal results.
Random Port Generator
Generate random TCP/UDP port numbers from well-known, registered, or dynamic ranges. Useful for network testing, Docker port mapping, and firewall configuration.
Chmod Calculator
Convert between numeric (755) and symbolic (u=rwx,g=rx,o=rx) chmod permission formats. See detailed breakdown for owner, group, and others.
Docker Run to Compose Converter
Convert docker run commands to docker-compose.yml format. Supports ports, volumes, environment variables, networks, restart policies, and container names.
Email Normalizer
Normalize email addresses by removing dots (Gmail), stripping +tags, and lowercasing. Process multiple emails at once for deduplication and cleaning.
Diff Checker
Compares two input texts side-by-side, highlighting inserted, deleted, and changed lines with distinct background colors.