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.

Nano ID Generator — Generate Compact URL-Safe IDs Online

Nano ID Generator creates short, URL-safe unique identifiers using a cryptographically random alphabet of 64 characters (A–Z, a–z, 0–9, _, -). The default size of 21 characters gives the same collision probability as UUID v4 (126 bits of randomness). Nano IDs are smaller than UUIDs (21 vs 36 characters), URL-safe without encoding, and widely used in JavaScript and TypeScript backends. All generation runs in the browser using the Web Crypto API.

Nano ID vs UUID vs ULID

UUID v4 is the most portable format: 32 hex digits in 8-4-4-4-12 groups (xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx). It is natively supported in PostgreSQL, MySQL, and most ORMs. The hyphenated format is 36 characters; without hyphens it is 32. The 4 and y prefix digits are version/variant markers, leaving 122 bits of actual randomness.

ULID (Universally Unique Lexicographically Sortable Identifier) encodes a 48-bit millisecond timestamp in the first 10 characters and 80 random bits in the remaining 16 characters. ULIDs sort chronologically in string order, making them useful for time-series data in systems that sort by primary key (e.g. DynamoDB). They use the Crockford Base32 alphabet (uppercase, no ambiguous characters like I, L, O, U).

Nano ID uses 64 URL-safe characters to pack more entropy per character than hex or Base32. At 21 characters it matches UUID v4's collision resistance while being 42% shorter. It has no timestamp component, so it does not sort chronologically — use ULID if ordered IDs matter. Nano ID is the best choice when you need short, dense, URL-safe identifiers for database keys, links, and slugs.

Collision Probability

The collision probability for N generated IDs of size S over an alphabet of A characters is approximately N² / (2 × A^S). For the default 21-character Nano ID (A=64): to reach a 1% collision probability you would need to generate 2.71 × 10^18 IDs — roughly 2.7 quintillion. At a rate of one million IDs per second, that would take about 86,000 years.

If you need shorter IDs (say, 12 characters for a URL slug), the collision probability rises significantly. At 12 characters (A=64): a 1% collision threshold is reached at ~3.9 × 10^10 IDs (~39 billion). For most applications this is still more than sufficient, but for extremely high-volume systems or globally shared namespaces, use the default 21 characters.

Common Use Cases

Generating short unique IDs for database primary keys
Creating URL-safe identifiers for shareable links and slugs
Generating short session or token IDs for web applications
Creating unique filenames for user-uploaded content
Replacing UUID v4 with a more compact identifier format

Frequently Asked Questions

What is a Nano ID?

Nano ID is a compact, URL-safe unique identifier. The default 21-character Nano ID uses 64 possible characters (A–Z, a–z, 0–9, _, -), giving 64^21 ≈ 2^126 possible values — the same collision probability as UUID v4. It was created by Andrey Sitnik and is widely used in the JavaScript/TypeScript ecosystem.

How does Nano ID compare to UUID v4?

Both have the same collision probability (~2^122 for UUID v4, ~2^126 for 21-character Nano ID). Nano ID is shorter (21 vs 36 characters), URL-safe without encoding (no hyphens that need to be escaped), and has a simpler structure. UUID v4 is more universally supported in databases and tools.

Can I use a custom alphabet with Nano ID?

Yes. SmartDevBox allows you to set a custom alphabet. You can restrict to alphanumeric-only (no _ or -), use only lowercase, or use any set of characters. Longer alphabets with the same size produce more entropy; shorter alphabets require a longer size for the same collision probability.

Is Nano ID cryptographically random?

Yes. SmartDevBox uses crypto.getRandomValues() (the Web Crypto API) to generate random bytes, which is cryptographically secure. The bytes are mapped to the alphabet using rejection sampling to avoid modulo bias.

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.

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