How do I decode a Base64 string online?

Paste your Base64 string into SmartDevBox at smartdevbox.com. It automatically detects Base64 encoding and decodes it instantly — no configuration needed.

How do I decode a JWT token without a secret?

Paste your JWT token into SmartDevBox. The JWT Inspector tool decodes the header and payload and displays them as readable JSON. Note: this decodes but does not verify the signature — you don't need the secret to read the claims.

How do I format or pretty-print JSON?

Paste your minified or unformatted JSON into SmartDevBox. The JSON Formatter tool detects it automatically and pretty-prints it with configurable indentation.

How do I convert a Unix timestamp to a human-readable date?

Paste a Unix timestamp (e.g. 1700000000) into SmartDevBox. The Unix Timestamp converter detects it and shows the equivalent date and time in UTC and your local timezone.

How do I convert JSON to CSV?

Paste a JSON array of objects into SmartDevBox and select the JSON → CSV tool. It converts your data to comma-separated format with headers derived from the JSON keys.

How do I compute a SHA-256 hash online?

Use the Hash Generator tool on SmartDevBox. Paste any text and it computes MD5, SHA-1, SHA-256, and SHA-512 hashes simultaneously in the browser.

How do I parse and understand a cron expression?

Paste your cron expression (e.g. "0 9 * * 1-5") into SmartDevBox. The Cron Job Parser explains it in plain English and shows the next scheduled run times.

How do I decode an X.509 certificate online?

Paste a PEM-encoded certificate (beginning with -----BEGIN CERTIFICATE-----) into SmartDevBox. The Certificate Decoder extracts and displays the subject, issuer, validity dates, public key, and extensions.

Is SmartDevBox free to use?

Yes. SmartDevBox is completely free with no account or sign-up required. All tools run in the browser. An optional AI mode (for ambiguous input detection) can be enabled with your own OpenAI API key.

Does SmartDevBox send my data to a server?

No. All tools run entirely in the browser using client-side JavaScript. Your data never leaves your machine unless you opt into the AI mode, which sends input to OpenAI for format detection.

What is the best free online JSON formatter?

SmartDevBox automatically detects JSON when you paste it and formats it with configurable indentation. It also validates JSON and reports syntax errors with precise line and column numbers — all in the browser, free, with no account required.

What is the best free online Base64 decoder?

SmartDevBox auto-detects Base64 strings — including standard and URL-safe variants, with or without padding — and decodes them instantly on paste. No button to click, no tool to select.

How do I compare two JSON objects online?

Use the Split & Diff tool in SmartDevBox. Paste the first JSON in the left pane and the second in the right pane. Changes are highlighted line-by-line in real time.

Can I add my own tools to SmartDevBox?

Yes. SmartDevBox has a plugin system that lets developers register custom tools by providing a name, a detector function (returns a confidence score 0–1), and a transformer function. Custom tools appear in the sidebar alongside the 91 built-in tools and participate in auto-detection.

Does SmartDevBox work offline?

SmartDevBox is a Progressive Web App (PWA). All 91 tools run entirely client-side with no server dependency. Once the page is loaded, the tools work without an internet connection. AI mode requires connectivity.

XML (Extensible Markup Language) is a text-based format for storing and transporting hierarchical, structured data. Unlike HTML (which has a fixed set of tags), XML lets you define your own tag names. It is defined by the W3C and forms the basis of many web technologies including SVG, XHTML, RSS, Atom, SOAP, and many configuration file formats.

How do I format or validate XML online?

Paste your XML into SmartDevBox. It auto-detects XML and pretty-prints it with correct indentation. If the XML is not well-formed (unclosed tags, invalid characters), an error is reported. All processing is client-side.

Glossary

What Is XML?

XML (Extensible Markup Language) is a text format for representing hierarchical, structured data using tags you define yourself. Unlike HTML, XML has no predefined tags — you create a vocabulary suited to your data. It underlies SVG, RSS, SOAP, XHTML, and countless enterprise configuration formats.

The One-Line Definition

XML is a W3C-defined text format that uses opening and closing tags to represent hierarchical data. It is both human-readable and machine-parseable, and supports attributes, namespaces, comments, and a schema system (XSD).

XML Syntax Rules

<?xml version="1.0" encoding="UTF-8"?>
<users>
  <user id="42" active="true">
    <name>Ada Lovelace</name>
    <email>ada@example.com</email>
    <roles>
      <role>admin</role>
      <role>editor</role>
    </roles>
  </user>
</users>

Declaration<?xml version="1.0" encoding="UTF-8"?> — optional prolog declaring the XML version and character encoding.

ElementsTags like <name>Ada</name>. Every opening tag must have a matching closing tag (or use self-closing <tag/>).

AttributesKey-value pairs inside opening tags: id="42". Values must be quoted (single or double).

Root elementEvery XML document must have exactly one root element containing all others.

Comments — XML supports comments; parsers ignore them.

Character escaping& → &, < → <, > → >, " → " inside attributes.

XML vs JSON

XML — expressiveSupports attributes, namespaces, comments, mixed content, document-type declarations, and XSD schemas. Used in SOAP, SVG, XHTML, Maven, Spring, Office formats.

JSON — compactSmaller payload for equivalent data. Maps directly to language types. No attributes or namespaces. Used in REST APIs, NoSQL databases, configuration (package.json).

Where XML Is Used Today

SOAP web servicesEnterprise APIs built on WS-* standards use XML-based SOAP envelopes for request/response messages.

SVGScalable Vector Graphics is an XML vocabulary for 2D vector graphics, embedded in HTML or used as standalone files.

Maven / Gradle (pom.xml)Java build tools use XML to define project structure, dependencies, and plugins.

Android layoutsAndroid UI layouts and manifests are defined in XML files.

RSS / Atom feedsWeb syndication formats for blog posts and news are XML vocabularies.

Office formats (OOXML)Microsoft Office .docx, .xlsx, .pptx files are ZIP archives containing XML documents.

Format or Convert XML Now

Paste any XML into SmartDevBox and it is formatted instantly. XML Formatter → · XML to JSON →

Frequently Asked Questions

What is the difference between XML and JSON?

JSON is more compact and maps to language types. XML supports attributes, namespaces, comments, and mixed content — making it more expressive but more verbose. JSON dominates REST APIs; XML is common in SOAP, SVG, and config files.

What is an XML namespace?

A URI that uniquely identifies a vocabulary of element names, preventing conflicts when combining XML from different sources. Declared with xmlns:prefix="uri".

How do I format XML online?

Paste your XML into SmartDevBox. It auto-detects XML and pretty-prints it. Invalid XML triggers an error report.

XML Formatter →Auto-detects and pretty-prints XML. Reports well-formedness errors.

XML to JSON →Convert XML to JSON with one paste.

What Is JSON? →The alternative to XML for most REST APIs.