LogoTOOLGENIE

Developer Cheat Sheet: Base64, UUID, JSON & Epoch

A practical developer cheat sheet for everyday encoding and debugging tasks: Base64 encode/decode, UUID generation, JSON formatting, and Unix epoch conversion.

9 min read

Most developers reopen the same four utilities every week: decode this Base64 blob, mint a UUID, tidy a JSON payload, convert an epoch timestamp. This cheat sheet links those jobs to free browser tools so you spend less time re-solving the same micro-problems.

1) Unix epoch ↔ readable date

Use when: logs, JWT exp, webhook payloads, database integer times.

Open the Epoch Converter.

Checklist:

  • Count digits (≈10 = seconds, ≈13 = milliseconds)
  • Read both UTC and local
  • Convert back when you need a query boundary

Deeper walkthrough: How to Convert a Unix Timestamp to a Date.

2) Base64 encode / decode

Use when: reading basic auth headers, data URLs, opaque config values, transport encodings.

Open Base64 Encode Decode.

Remember:

  • Base64 is not encryption
  • Decoding broken padding often means you copied a truncated string
  • Prefer UTF-8 aware decoding for text payloads

3) UUID generation

Use when: fixture IDs, idempotency keys, fake row IDs, correlating requests.

Open the Random UUID Generator.

Tips:

  • Use UUIDs for uniqueness, not for security secrets
  • Keep formatting consistent (lowercase vs uppercase) across a codebase
  • Generate several at once when seeding test data

4) JSON format / inspect / edit

Use when: API responses are minified, configs fail validation, or you need a quick structural edit.

Open the JSON Editor.

Workflow:

  1. Paste the payload
  2. Format/validate
  3. Fix trailing commas / type mismatches
  4. Copy the cleaned result back into your tool or ticket

5) Bonus utilities developers reach for next

Job Tool
Hash a string for checksums Hash Generator
Compare two configs/snippets Text Diff Checker
Generate sample passwords/secrets for local tests Password Generator
Convert city times for on-call handoff World Time Zone Converter

Suggested bookmark bar order

  1. Epoch Converter
  2. Base64 Encode Decode
  3. Random UUID Generator
  4. JSON Editor
  5. Hash Generator

That set covers most “I just need to decode this thing” moments without opening an IDE.

Frequently Asked Questions (FAQ)

What developer utilities should I bookmark first?

Start with an epoch converter, Base64 encoder/decoder, UUID generator, and JSON editor. Those four cover a large share of day-to-day debugging.

Is Base64 encryption?

No. Base64 is encoding for safe transport of binary data as text. Anyone can decode it. Do not treat it as a security control.

Should I generate UUIDs in the browser?

Yes for many app and test workflows. A browser UUID generator is convenient for fixtures, request IDs, and quick samples.

Why do JSON tools matter if my editor can format JSON?

Online/browser JSON tools are useful for quick validation, sharing a cleaned snippet, or inspecting payloads outside your IDE.

How do I avoid seconds vs milliseconds bugs with epoch time?

Check digit length and confirm units before converting. A dedicated epoch converter makes that check faster than mental math.

Related free tools

Related guides

Browse more guides on the ToolGenie Blog.