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.

URL Encoder — Percent-Encode Strings for URLs Online

URL Encoder applies percent-encoding (also called URI encoding) to any string, converting special characters to their %XX equivalents. This is required whenever arbitrary text needs to appear in a URL query parameter or path segment. SmartDevBox uses the standard encodeURIComponent() encoding, which encodes all characters except A–Z, a–z, 0–9, -, _, ., and ~.

Common Use Cases

Encoding query parameter values containing spaces or special characters
Building URLs programmatically with dynamic user input
Encoding OAuth redirect_uri and state parameters
Preparing strings for inclusion in HTML href attributes

Frequently Asked Questions

What is URL encoding?

URL encoding (percent-encoding) converts characters that are not allowed in URLs into a % followed by two hexadecimal digits. For example, a space becomes %20, and & becomes %26.

What is the difference between encodeURI and encodeURIComponent?

encodeURI encodes a full URL and leaves characters like /, :, and ? intact. encodeURIComponent encodes a URL component (like a query value) and encodes those structural characters too. SmartDevBox uses encodeURIComponent.

Privacy & Security

This tool runs entirely in your browser using client-side JavaScript. No data is sent to a server — your input never leaves your machine. SmartDevBox has no account system, no usage tracking, and no paid tier. See the Privacy & Security page for full details.

URL DecoderDecode any percent-encoded URL string back to readable text instantly in your browser. Free, no sign-up, 100% client-side.
URL ParserParse any URL into its protocol, host, path, query parameters, and hash fragment instantly. Free, no sign-up, 100% client-side.
Base64 EncoderEncode any text or string to Base64 instantly in your browser. Free, no sign-up, 100% client-side. Results copy with one click.
HTML EncoderConvert special characters like < > & " to HTML entities instantly in your browser. Free, no sign-up, 100% client-side.