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.

Core Feature

Auto Format Detection

Paste anything. SmartDevBox identifies the format and applies the right tool — instantly, with no clicking through menus.

What is Auto Detection?

SmartDevBox includes a real-time format detection engine that runs the moment you paste or type text into the input area. It scores your input against every one of the 91+ built-in tools simultaneously, identifies the most likely format with a confidence percentage, and automatically applies the correct tool — all before you have time to look for a menu.

Instead of navigating a sidebar of tools and guessing which one applies, you paste once and the right tool fires. A detection bar below the input shows which formats were recognised and at what confidence level, so you always know what the engine saw.

How It Works

Every tool in SmartDevBox registers a detector function alongside its transformer. When input arrives, the engine calls every detector and collects a normalised confidence score from 0 to 1.

Score > 0.8Tool executes automatically — result appears immediately.

Score 0.3 – 0.8Shown as a clickable suggestion chip. One click to switch.

Score < 0.3Quietly excluded — no noise from irrelevant tools.

A 600 ms debounce prevents the engine from thrashing on every keystroke, so typing feels instant while detection fires only when you pause.

Formats Recognised Automatically

These formats are detected and processed without any manual selection:

Base64Standard and URL-safe variants, with or without padding

JSONObjects, arrays, strings, numbers — any valid JSON value

JWT tokensThree-part dot-separated Base64url strings

XML / HTMLTag-based markup, both well-formed and loose

SQL queriesSELECT, INSERT, UPDATE, DELETE, CREATE, and more

URLsFull URIs with protocol, host, path, and query string

Unix timestamps10-digit (seconds) and 13-digit (milliseconds) integers

X.509 certificatesPEM-encoded blocks beginning with -----BEGIN CERTIFICATE-----

Cron expressionsStandard five-field and extended six-field syntax

Hex stringsRaw byte sequences in hexadecimal notation

Color codesHEX (#rrggbb), RGB, HSL, HSV values

YAMLIndented key-value documents

CSV / TSVComma- or tab-separated tabular data

MarkdownHeading, link, code-block, and list syntax

UUIDsStandard 8-4-4-4-12 hyphenated format

ULIDs26-character Crockford Base32 strings

Base32RFC 4648 encoded strings

Roman numeralsI through MMMCMXCIX

H:M:S durationsHours:minutes:seconds notation

AI-Assisted Detection (Optional)

AI mode is disabled by default and requires your own OpenAI API key. All 91+ tools work fully without it.

For ambiguous inputs where the heuristic engine is uncertain, SmartDevBox can optionally call the OpenAI API to classify the format. When active, an AI indicator appears in the detection bar. All tool processing still happens client-side; only the format-detection query is sent to OpenAI.

Why This Matters

Developer workflows involve constant context-switching: decode a JWT from a log file, format JSON from an API response, parse a timestamp from a database export, check a certificate expiry — often in the same five minutes. Having to manually select the right tool each time adds friction and breaks focus. Auto-detection eliminates that friction entirely.

SmartDevBox Auto-Detection vs Manual Tool Selection

Most developer toolboxes — including CyberChef, DevUtils, and single-purpose sites like base64decode.org or jsonlint.com — require you to choose the right tool before you can process your input. SmartDevBox inverts this model: you paste first, and the tool selection happens automatically.

Traditional approachOpen tool → select format → paste input → click submit → see result. Requires 3–5 deliberate steps per task.

SmartDevBox approachPaste input → result appears. One step. The format identification is automated by the detection engine.

This matters most when you are context-switching rapidly — decoding a Base64 blob from a log file, then formatting a JSON API response, then parsing a timestamp from a database export. Each paste triggers the correct tool automatically, with no navigation required between them.

Frequently Asked Questions

What if my input matches more than one format?

The tool with the highest confidence score is applied automatically. All other matching tools appear as chips in the Detection Bar. Clicking any chip switches the active tool instantly.

Can I disable auto-detection and pick a tool manually?

Yes. Click any tool in the sidebar to lock it as the active tool, bypassing auto-detection. The sidebar is always accessible via the Tools button in the navigation bar.

Does auto-detection send my data anywhere?

No. The heuristic detection engine runs entirely in the browser. Only the optional AI mode sends a format-detection request to OpenAI. See the Privacy & Security page for full details.