Lumatic Labs: Blog and Guides
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New guides and posts from Lumatic Labs: small, useful, private-by-default web tools that run entirely in your browser.
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Convert JSON to CSV in Python: pandas Guide
Convert JSON to CSV in Python with pandas: read_json and json_normalize for nested data, the csv module fallback, and the errors you will hit.
How to Apply a JSON Patch in JavaScript, Python, Go and Java
Apply an RFC 6902 JSON Patch with runnable snippets for JavaScript, Python, Go, Java and C#: install lines, complete code, the six ops.
Pretty Print JSON in Python: json.dumps Guide
Pretty print JSON in Python with json.dumps(indent=2): the one-liner, reading and writing files, the terminal json.tool, and the errors you will hit.
URL Parser: Break a URL Into Its Parts
See every part of a URL: scheme, host, port, path, query string and fragment. How parsers work in Python and JavaScript, plus a live tool.
Image to Base64: Encode and Decode Data URIs
Convert images to Base64 data URIs for HTML, CSS and JSON, and decode Base64 back to an image. Pros, size limits, and the in-browser tool.
AI Content Pipeline: Correct but Boring
Our AI content pipeline produced a post that was correct, optimized, and boring. Here is the six-point fix we shipped, so your AI content avoids the same trap.
UUID in Python: Generate v4, v7 and More
Generate UUIDs in Python with the uuid module: uuid4 for random IDs, uuid7 for time-ordered ones, plus validation and bulk generation.
JSON Compare: How to Compare Two JSON Files
Compare two JSON files and spot real differences: normalize first, use an online checker, or diff in git. Three methods that survive nested objects.
Discord Timestamps: Format Codes and Examples
How Discord timestamps work: every timestamp code from t to F, dynamic vs static times, a full format table, and a quick way to build the code.
SHA256 File Checksum: Verify Files on Any OS
Check a file's SHA256 checksum on Windows, macOS and Linux, compare it against the published hash, and confirm a download was not corrupted.
Unix Timestamp to Excel Date: 3 Formulas
Convert a Unix timestamp to an Excel date with =(A1/86400)+DATE(1970,1,1). Seconds, milliseconds, and back again, plus the timezone trap.
UUID v7: What It Is, How to Generate One
UUID v7 generates time-ordered IDs that keep database indexes fast. How it works, v4 vs v7, and one-click generation in your browser.
UUID Versions Explained: v4, v7 and When to Use Each
All 8 UUID versions in plain language: what v4 and v7 actually are, how they differ, and which to pick for database keys, request IDs and logs. No jargon.
In the directory since 25 Oct 2026 · last checked 9 Nov 2026 · RSS