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FeuTex · free tools runs in-browser no bloat built by LiMiT

Online Converter

Convert common text formats in one place. This tool runs fully client-side (no uploads): JSON, CSV, Base64, URL encoding, HTML escaping, text case, number bases, and Unix timestamps.

Category: General · URL: /tools/online-converter.html
Tip: Ctrl/⌘ + Enter to convert. Use Swap to chain conversions.
Related tools: Online Generator · SEO Checker · Cron Formatter · Markdown Table Generator · XML Checker · Hash Formatter · SQL Generator
Privacy: runs locally in your browser. No uploads, no tracking scripts.

How to use

Pick a conversion mode, paste your input, then convert and copy.

  1. Select a mode (e.g., JSON → CSV, Base64 decode, URL encode).
  2. Paste text into the input box.
  3. Adjust options (CSV delimiter, timestamp units) if shown.
  4. Click Convert (or press Ctrl/⌘ + Enter).
  5. Copy the output or swap it back into the input to chain conversions.
Keywords this page targets (natural cluster): online converter, text converter online, json prettify online, json minify online, json to csv converter, csv to json converter, base64 encode online, base64 decode online, url encode online, url decode online, html escape online, html unescape online, snake case converter, kebab case converter, title case converter, uppercase lowercase converter, unix timestamp to date, date to unix timestamp, decimal to hex converter, hex to decimal converter
Secondary intents covered: Convert pasted data between formats without installing tools, Prettify or minify JSON for readability or compact storage, Transform JSON arrays into CSV for spreadsheets, Turn CSV headers/rows into JSON objects, Encode/decode Base64 safely (including Unicode text), Encode/decode URL components for query strings, Escape/unescape HTML entities for safe rendering, Normalize text casing for slugs/identifiers, Convert Unix timestamps to ISO time and back

FAQ

Does this online converter upload my data?

No. Conversions run in your browser and the tool does not send network requests.

What JSON shapes work for JSON → CSV?

Best results come from an array of objects (one object per row). Nested values are JSON-stringified into a single CSV cell.

Why does CSV → JSON keep numbers as strings?

CSV has no native types, so the tool keeps values as strings to avoid incorrect guessing.

Why does Base64 decode fail sometimes?

The input may not be valid Base64 or may include extra characters. Remove whitespace/invalid chars and try again.

URL encode vs full URL encode—what does this do?

This encodes/decodes a URL component (e.g., query value) using encodeURIComponent/decodeURIComponent, not a full URL rewrite.

How does timestamp auto-detect work?

Auto treats ~10-digit values as seconds and ~13-digit values as milliseconds. You can override using the Timestamp unit option.

Can I chain conversions (e.g., JSON → CSV then Base64)?

Yes. Convert, then click Swap to move output back into input and choose a new mode.