Tools

Tool datasette.io news preview

The datasette.io website has a news section built from this news.yaml file in the underlying GitHub repository. The YAML format looks like this:

- date: 2026-04-15
  body: |-
    [Datasette 1.0a27](https://docs.datasette.io/en/latest/changelog.html#a27-2026-04-15) changes how CSRF protection works in a way that simplifies form and API integration, and introduces a new `RenameTableEvent` for when a table is renamed by a SQL query.
- date: 2026-03-18
  body: |-
    ...

This format is a little hard to edit, so I finally had Claude build a custom preview UI to make checking for errors have slightly less friction.

I built it using standard claude.ai and Claude Artifacts, taking advantage of Claude's ability to clone GitHub repos and look at their content as part of a regular chat:

Clone https://github.com/simonw/datasette.io and look at the news.yaml file and how it is rendered on the homepage. Build an artifact I can paste that YAML into which previews what it will look like, and highlights any markdown errors or YAML errors

16th Apr 2026, 12:18 am · vibe-coding, claude, tools, datasette

Tool Gemini 3.1 Flash TTS — Convert text to natural-sounding speech using Google's Gemini 3.1 Flash TTS model with support for both single-speaker and multi-speaker conversation modes. The tool allows you to customize voice selection, apply directorial tags like `[whisper]` and `[short pause]` for dynamic delivery, and download the generated audio as a WAV file. Requires a valid Gemini API key to function.

See my notes on Google's new Gemini 3.1 Flash TTS text-to-speech model.

15th Apr 2026, 4:41 pm · gemini, google

Tool SQLite Query Result Formatter Demo — Format SQLite query results in 20 different styles including box-drawing tables, CSV, JSON, HTML, Markdown, and more using this interactive WebAssembly-based demonstration. Adjust formatting options like column headers, screen width, NULL display values, and border styles in real-time to see how your SQL queries render across all available output modes. The demo database includes sample tables for employees, products, and orders with pre-built example queries showcasing each formatting style.

See my notes on SQLite 3.53.0. This playground provides a UI for trying out the various rendering options for SQL result tables from the new Query Result Formatter library, compiled to WebAssembly.

11th Apr 2026, 7:35 pm · tools, sqlite

Tool GitHub Repo Size — Check the size of any GitHub repository by entering the owner and repository name or pasting a GitHub URL. The tool fetches repository data from the GitHub API and displays the total size in kilobytes, megabytes, or gigabytes depending on the repository's scale. Results are automatically saved to the browser URL, allowing you to share or revisit repository size checks.

GitHub doesn't tell you the repo size in the UI, but it's available in the CORS-friendly API. Paste a repo into this tool to see the size, for example for simonw/datasette (8.1MB).

9th Apr 2026, 9:31 pm · cors, github

Tool Cleanup Claude Code Paste — Clean up Claude Code terminal output by removing the ❯ prompt character, fixing whitespace from line wrapping, and joining broken lines into readable paragraphs. Paste your terminal text into the input field and the cleaned output will appear automatically, ready to copy to your clipboard.

Super-niche tool this. I sometimes copy prompts out of the Claude Code terminal app and they come out with a bunch of weird additional whitespace. This tool cleans that up.

6th Apr 2026, 2:55 am · tools, claude-code

Tool Syntaqlite Playground — # Syntaqlite Playground

Lalit Maganti's syntaqlite is currently being discussed on Hacker News thanks to Eight years of wanting, three months of building with AI, a deep dive into how it was built.

This inspired me to revisit a research project I ran when Lalit first released it a couple of weeks ago, where I tried it out and then compiled it to a WebAssembly wheel so it could run in Pyodide in a browser (the library itself uses C and Rust).

This new playground loads up the Python library and provides a UI for trying out its different features: formating, parsing into an AST, validating, and tokenizing SQLite SQL queries.

Update: not sure how I missed this but syntaqlite has its own WebAssembly playground linked to from the README.

5th Apr 2026, 7:32 pm · sql, ai-assisted-programming, sqlite, tools, agentic-engineering

Tool Pretext — Under the Hood — Explore how pure-JavaScript text measurement and line breaking work through an interactive visualization of the Pretext library's pipeline. This tool demonstrates each stage from raw text input through whitespace normalization, word segmentation, canvas-based width measurement, and arithmetic-based line breaking, with live verification against actual DOM rendering.

See my notes on Pretext here.

29th Mar 2026, 7:59 pm

Tool Python Vulnerability Lookup — Search Python packages for known security vulnerabilities by pasting a `pyproject.toml` or `requirements.txt` file, or by loading dependencies directly from a GitHub repository. The tool queries the OSV.dev vulnerability database and displays detailed information about any identified vulnerabilities, including severity levels, affected version ranges, and links to full disclosure reports.

I learned that the OSV.dev open source vulnerability database has an open CORS JSON API, so I had Claude Code build this HTML tool for pasting in a pyproject.toml or requirements.txt file (or name of a GitHub repo containing those) and seeing a list of all reported vulnerabilities from that API.

29th Mar 2026, 6:46 pm · tools, python, supply-chain, vibe-coding, security

Tool DNS Lookup — # DNS Lookup Documentation

TIL that Cloudflare's 1.1.1.1 DNS service (and 1.1.1.2 and 1.1.1.3, which block malware and malware + adult content respectively) has a CORS-enabled JSON API, so I had Claude Code build me a UI for running DNS queries against all three of those resolvers.

22nd Mar 2026, 7:16 pm · dns, cors, cloudflare

Tool Merge State Visualizer — # CRDT Merge State Visualizer

Bram Cohen wrote about his coherent vision for the future of version control using CRDTs, illustrated by 470 lines of Python.

I fed that Python (minus comments) into Claude and asked for an explanation, then had it use Pyodide to build me an interactive UI for seeing how the algorithms work.

22nd Mar 2026, 6:57 pm · vcs, pyodide, bram-cohen, crdt

Tool TURBO.COM — 39,731 Bytes Deconstructed — Explore an interactive breakdown of Turbo Pascal 3.02A's 39,731-byte executable, mapping each function from the header and display system through the parser and symbol table. Navigate the binary segments with an overhead visualization and detailed hex dumps with annotated disassembly, revealing how a complete compiler, editor, and runtime fit within the constraints of 1986 DOS memory while routing all file I/O through a single INT 21h dispatcher gateway.

20th Mar 2026, 11:48 pm

Tool Sorting algorithms — Explore and compare different sorting algorithms through interactive animated visualizations that display how each algorithm organizes data in real-time. The tool allows you to adjust dataset size and animation speed, run individual algorithms step-by-step or continuously, and race multiple algorithms simultaneously to see which performs best. Each algorithm includes detailed complexity analysis and visual indicators for comparisons, swaps, and sorted elements.

11th Mar 2026, 10:35 pm · sorting

Tool SQLite Bytecode Explorer — Explore SQLite's Virtual Database Engine (VDBE) by analyzing the bytecode that SQLite generates when compiling SQL queries. This tool runs the `EXPLAIN` command on your SQL statements and annotates each instruction with detailed explanations of what it does, from cursor management and table scans to index lookups and aggregate functions.

11th Mar 2026, 8:44 pm

Tool MP3 Inspector — Extract ID3 metadata and file information from MP3 audio files using this browser-based tool. Upload an MP3 file by dragging it onto the drop zone or selecting it through the file picker, and the inspector will parse and display all available tags including title, artist, album art, technical encoding details, and embedded URLs. The tool organizes metadata into categorized sections and provides a raw JSON view for advanced inspection of the complete tag data.

5th Mar 2026, 1:30 pm

Tool NICAR 2026 Schedule — Browse the NICAR 2026 conference schedule with powerful search and filtering capabilities. This interactive schedule viewer lets you explore sessions across multiple days, filter by session type, track, and skill level, and save your favorite sessions for quick access. The schedule works offline using cached data and automatically syncs updates when you're back online.

The NICAR data journalism conference provides a copy of the schedule as CORS-enabled JSON, so I vibe coded my own mobile-friendly schedule app to help me keep track of the sessions I want to attend.

4th Mar 2026, 9:34 pm · cors, vibe-coding, nicar

Tool GIF Optimizer (gifsicle WASM) — Optimize animated GIF files using gifsicle compiled to WebAssembly, with all processing occurring directly in your browser without server uploads. The application offers preset optimization profiles ranging from lossless compression to aggressive lossy reduction, along with manual control over parameters like color palette size, scaling, and dithering methods.

1st Mar 2026, 12:14 pm

Tool markdown-copy component — The `<markdown-copy>` component renders markdown content with built-in controls for viewing the rendered output and copying or viewing the source code. It provides an interactive interface with a menu button that allows users to toggle between the formatted markdown display and the raw markdown source, as well as quickly copy the markdown text to the clipboard.

28th Feb 2026, 9:54 pm

Tool Animated Word Cloud — View animated word cloud visualizations that use an Archimedean spiral placement algorithm to position words on a canvas. Each word spirals outward from the center until it finds an unoccupied space, with grid-based spatial indexing accelerating collision detection to handle large datasets efficiently. Control the animation playback speed, step through frames manually, download the final result as a PNG, or paste your own text to generate a custom word cloud.

27th Feb 2026, 10:39 pm

Tool Unicode Explorer — Binary Search Over HTTP — View Unicode characters and their properties through an interactive binary search algorithm that makes real HTTP Range requests to fetch individual records from a binary database. Enter a character or Unicode codepoint to see each step of the search visualized in a network log, including fetch times and comparisons.

27th Feb 2026, 4:01 pm · http-range-requests, unicode

Tool Mobile Data Tables: Responsive Patterns Demo — # Mobile Data Tables: Responsive Patterns Demo

26th Feb 2026, 5:49 am

Tool Contact form — Submit contact information through this responsive form that provides real-time validation using native HTML5 attributes and CSS-only feedback. The form validates required fields including name, email, and message content, displaying checkmarks for valid inputs and error messages for invalid entries without requiring any JavaScript.

19th Feb 2026, 2:41 pm

Tool Gemini Prompt — Generate responses from Google's Gemini API with support for system prompts, model selection, and streaming output. The interface stores your API key securely in local storage and maintains a history of system prompts for quick reuse. Markdown formatting is automatically rendered in the output area, and you can copy responses to your clipboard with a single click.

18th Feb 2026, 6:58 am

Tool Gradient image generator — Generate customizable gradient images with multiple pattern overlays and effects. This tool provides controls for linear, radial, and conic gradients with adjustable colors, along with options for layering various patterns including noise, geometric shapes, and textures. Additional features include film grain, vignetting, and blend mode controls to fine-tune the visual appearance, with the ability to export the final result as a PNG image or save and restore settings as JSON.

15th Feb 2026, 9:05 pm

Tool Python Comment Stripper — Remove all comments from Python source code while preserving strings, docstrings, and code structure using the `tokenize` module running on Pyodide. Paste your Python code into the input panel, and the tool automatically strips comments in real-time, with the ability to copy the cleaned output to your clipboard. The application runs entirely in the browser without requiring a local Python installation.

14th Feb 2026, 12:52 am

Tool Pyodide REPL — Execute Python code directly in your web browser using Pyodide, a port of CPython to WebAssembly. This REPL provides an interactive Python environment with support for multiple Pyodide versions, single-line and multi-line input modes, and command history navigation. The interface is optimized for both desktop and mobile devices, with a dark theme and responsive layout that prevents content from being hidden behind on-screen keyboards.

10th Feb 2026, 10:54 pm

Tool GIF Dissector — Parse and visualize animated GIF files by extracting individual frames, timing data, color palettes, and detailed metadata. Upload a GIF file to instantly decompose it into its constituent frames with precise delay measurements, disposal methods, transparency information, and global color table analysis. The tool renders composited frames to show exactly how the animation appears, while providing comprehensive technical details about the image structure and properties.

10th Feb 2026, 3:08 pm

Tool SQLite AST — Parse SQLite SELECT queries into abstract syntax trees and view the results in JSON and Python representations. This tool uses the sqlite-ast library running in your browser via Pyodide to analyze SQL syntax and display both the dictionary-based parse tree and a rich pretty-printed representation. It supports complex queries including compound selects, common table expressions, and window functions, and can display partial parse results when encountering syntax errors.

30th Jan 2026, 6:26 am

Tool Minesweeper — Play a classic Minesweeper game directly in your browser with support for three difficulty levels: Easy, Medium, and Hard. Use left-click to reveal cells and right-click to place flags, or toggle between reveal and flag modes on mobile with long-press support. The game features a timer to track your speed, mine counter to monitor remaining flags, and immediate visual feedback when you win or hit a mine.

26th Jan 2026, 9:46 pm

Tool Directory Explorer Demo — Explore the contents of a local directory in your browser with an interactive file tree viewer and search functionality. This tool demonstrates the capabilities of the `webkitdirectory` input attribute to access folder structures and analyze file distribution. Once a directory is selected, view detailed statistics about file counts, total size, and file type breakdown, with options to filter by name and file extension.

25th Jan 2026, 6:39 pm

Tool Bookmarklets Collection — Access a collection of practical bookmarklets for web development and general browsing tasks. Each bookmarklet can be installed by dragging it to your bookmarks bar on desktop browsers or by copying the code for mobile Safari. The collection includes tools for revealing page anchor points and viewing page source code with formatting options, all presented with detailed documentation and source code inspection capabilities.

18th Jan 2026, 4:54 pm

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