너멜엠 NumLM Tools tools.numlm.com
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NumLM Tools (너멜엠) is a collection of free calculators, converters, text, developer and file tools. Everything runs inside your browser — this page explains what that means and how the site works.

Your data never leaves your device

Every tool computes locally with JavaScript. Nothing you type, paste or drop is uploaded to a server — there is no account, no upload queue and no “save” feature that could expose your data.

The only network requests after a page loads are for the exchange-rate table in the Currency Converter (a read-only fetch from the European Central Bank feed) and for fonts. You can verify this yourself: open your browser’s DevTools → Network tab while you use a tool.

There is no analytics script. Like every web server, ours keeps a standard access log (page path, time, IP address, browser) that we summarise into aggregate visit counts; the query string — where tool inputs live — is never written to it, and the report shows IP addresses anonymised.

  • Large text inputs (JSON, diffs, word counter…) are kept in this browser’s localStorage so a reload does not lose them. “Clear” removes them.
  • Regex and Diff share their state in the URL fragment (after #), which browsers never send to servers.
  • File tools work offline once the page has loaded.

Using a tool

  • Results update as you type — there is no Calculate button. Heavy file operations have an explicit run button.
  • Every result has a Copy button. The Share link button copies a URL that reproduces your current inputs.
  • Each tool page ends with “How to use” steps and an FAQ.
  • Enter numbers freely: 1,000, $50, 15% and −3 are all understood.

Language, units, text size and theme

  • Language is detected from your browser (then your time zone). Change it any time with the selector in the header; the choice is remembered on this device.
  • Units and currency default to your language’s country (metric / imperial, °C / °F, KRW / USD…). Override them site-wide with the ⚖ button in the header, or per tool inside the tool itself. A value in a shared link always wins.
  • Text size: the Aa button offers Default, Medium and Large for easier reading. The whole site scales.
  • Theme follows your system and can be toggled with the sun/moon button.

Shortcuts and favourites

  • Press / anywhere to jump to the search box; use ↑ ↓ and Enter to open a result.
  • Ctrl/Cmd + Enter runs the action in tools that have one (e.g. Format JSON).
  • ☆ Save on a tool page pins it to “Your tools” on the home page; recently used tools appear there automatically.

File tools: formats and limits

  • Images: JPG, PNG, WebP, GIF, BMP and SVG can be read; output is JPG, PNG or WebP. HEIC/AVIF output is not supported by browsers without a large codec, so it is not offered.
  • PDF: merge, split, rotate, images → PDF and PDF → images. Encrypted PDFs must be unlocked first; compression and passwords are intentionally not offered because browser libraries cannot do them reliably.
  • There is no file-count or size limit, but very large files depend on your device’s memory. If a file fails, the row shows the reason.
  • Download all as ZIP bundles every result in one file.

Accuracy

Formulas follow standard definitions (e.g. WHO BMI bands, exact SI conversion factors, cent-precision amortization). Finance results are estimates for planning, not offers; exchange rates are daily ECB reference rates, not bank rates.

Copyright & open-source licences

© 2026 너멜엠 NumLM. The site’s own code, texts, design and the NL mark are copyrighted — all rights reserved. Using the tools is free for personal and commercial purposes; copying the site or its code is not.

The site is built on the open-source components below. Each is used under its own licence, whose terms and copyright notices are kept as required:

Feedback

Found a bug or missing a tool? Tell us at numlm.com.