ZentoMedia
en
Browser Tools by ZentoMedia

Useful browser tools for common developer tasks.

A growing set of browser utilities for decoding, transforming, inspecting, and generating data right where you work.

Runs entirely in your browser
No signup or install required
Made for common developer tasks

Built by zentomedia.net

Binary inspectionLive

ASN.1 Lens

Inspect BER and DER structures directly in the browser with format detection, a readable tree view, and zero server round-trips.

Decode certificates, keys, and binary blobs without leaving zentomedia.net.

Client-sideNo signupFast utilityFile upload
  • Accepts PEM, Base64, Hex, and uploaded files.
  • Detects the input format and normalizes the payload before parsing.
  • Shows offsets, lengths, and previews in a readable decode tree.
Use this tool
URL transformationLive

URL Encode / Decode

Encode or decode URLs, query strings, and parameter values directly in the browser.

Open the URL codec directly when you just need paste, transform, and copy.

Client-sideNo signupFast utility
  • Handles full URLs, query strings, and individual parameter values.
  • Useful for debugging redirects, callback URLs, and encoded request data.
  • Runs locally in the browser with no server round-trip.
Use this tool
Base64 transformationLive

Base64 Encode / Decode

Convert UTF-8 text to and from Base64 locally in the browser without losing Unicode characters.

Useful for tokens, payload samples, fixtures, and quick copy-paste debugging.

Client-sideNo signupFast utility
  • Uses UTF-8 aware helpers for readable text, not ASCII-only shortcuts.
  • Good for payload samples, test data, tokens, and quick debugging loops.
  • Runs fully client-side with no dependency on a backend service.
Use this tool
HTML transformationLive

HTML Entity Encode / Decode

Escape or unescape HTML entities such as <, >, &, quotes, and apostrophes without leaving the page.

Helpful for snippets, CMS fields, email templates, and quick markup cleanup.

Client-sideNo signupFast utility
  • Escapes and unescapes common HTML entities for safe copy and inspection.
  • Useful for content fields, snippets, email templates, and rendered text checks.
  • Runs instantly in the browser with no account or server dependency.
Use this tool
JSON inspectionLive

JSON Decode Tree

Parse JSON into an expandable tree, unwrap JSON string layers, and decode nested fields locally in the browser.

Made for API payloads, response.body strings, and quick DevTools-style inspection.

Client-sideNo signupFast utility
  • Parses valid JSON objects and arrays into an expandable local tree.
  • Automatically unwraps JSON strings when the parsed result is still JSON text.
  • Lets you parse nested string fields such as response.body with one click.
Use this tool
Identifier generationLive

GUID / UUID Generator

Generate batches of UUID v4 values in the browser with flexible formatting, Base64 variants, and copy-ready output.

Generate UUID values directly in the browser.

Client-sideNo signupFast utility
  • Generates 1 to 1000 UUID v4 values using the Web Crypto API.
  • Supports canonical text, braces, uppercase, quotes, commas, and batch-friendly output.
  • Can emit raw-byte Base64, RFC 7515 Base64URL, and optional URL-encoded output.
Use this tool
2FA generationLive

2FA / TOTP Code Generator

Generate 2FA codes locally in your browser, import otpauth QR images, and keep shared secrets off third-party services.

Use TOTP locally for quick 2FA checks, QR image import, and copy-ready output.

Client-sideNo signupFast utilityFile upload
  • Supports plain secrets, optional label|SECRET lines, and otpauth://totp URIs.
  • Imports QR data from an image directly in your browser.
  • Runs fully client-side with no secret upload to a server or external API.
Use this tool
Calendar referenceLive

Vietnamese Lunar Calendar

View a Gregorian month alongside the Vietnamese lunar calendar, convert dates both ways, and inspect Can Chi details directly in the browser.

A browser-native am lich and perpetual calendar tool for everyday lookups.

Client-sideNo signupFast utility
  • Shows a full month grid with solar dates and matching lunar dates.
  • Converts Gregorian dates to Vietnamese lunar dates and converts lunar dates back to solar dates.
  • Includes leap-month handling plus Can Chi details for the selected day, month, and year.
Use this tool
Pronunciation learningLive

English Pronunciation Tool

Look up a word or phrase, then open Oxford, Cambridge, YouGlish, and Google Translate quickly from one place.

A practical browser workbench for quick pronunciation lookups and repeated listening.

Client-sideNo signupFast utility
  • Builds reliable Oxford, Cambridge, YouGlish, and Google Translate links from a normalized query.
  • Lets you choose a native translation language, with Vietnamese as the default.
  • Keeps recent searches and favorites locally for fast daily review.
Use this tool