Online Tools Suite

Efficient, free, local text and developer tools. All data is processed only in your browser.

JSON VisualizerTools

Format, validate and visualize JSON data

Status: Waiting for input
Size: 0 chars

Paste your JSON here and watch the magic happen

JSON VisualizerTools — Tutorial

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data interchange format proposed by Douglas Crockford in 2001. It is based on JavaScript object literal syntax but is language-independent, and has become one of the most commonly used data transmission formats in web development. Almost all modern programming languages natively support JSON parsing and generation.

JSON is designed to be concise, readable, and easy for machines to parse. Compared to XML, JSON is more compact, more efficient to parse, and more readable. RESTful APIs, configuration files, NoSQL databases, and many other scenarios heavily use JSON format.

JSON Basic Syntax

JSON supports the following data types:

  • Object: Wrapped in curly braces {}, containing key-value pairs where keys must be double-quoted. For example: {"name": "John", "age": 25}
  • Array: Wrapped in square brackets [], containing an ordered list of values. For example: [1, 2, 3, "hello"]
  • String: Unicode text wrapped in double quotes
  • Number: Integer or floating-point numbers, e.g. 42 or 3.14
  • Boolean: true or false
  • Null: null

How to Use This Tool?

  1. Paste or enter your JSON data in the input area
  2. The tool auto-detects and formats, no manual clicking needed
  3. Click the Format button to beautify minified JSON with indentation for readability
  4. Click Minify to remove all whitespace
  5. Click Validate to check syntax correctness
  6. After formatting, click nodes to collapse/expand for navigating large JSON structures

Common Use Cases

  • API Debugging: Format JSON data returned by APIs to quickly locate problematic fields
  • Config Editing: Check syntax errors in JSON config files (package.json, tsconfig.json)
  • Data Migration: Review and validate exported JSON data for completeness
  • Learning: Intuitively understand JSON structure through tree visualization
  • Code Debugging: Minify JSON to reduce network transfer size

FAQ

Q: Why can't my JSON be parsed?

The most common causes include: using single quotes instead of double quotes, trailing commas after the last element, comments (JSON doesn't support comments), missing quotes, etc. This tool's smart parser can auto-fix some common errors.

Q: Is my data safe?

Completely safe. All data is processed locally in your browser and is never uploaded to any server. Data is automatically cleared when you close the page.

Q: What size JSON files are supported?

This tool supports JSON data up to several MB, depending on your browser performance. For very large JSON files, consider using a professional desktop tool.

QR Code Generator

Convert text to QR code image

QR code will appear here

QR Code Generator — Tutorial

What are QR Codes?

QR Code (Quick Response Code) is a type of matrix barcode invented by the Japanese company Denso Wave in 1994. Compared to traditional one-dimensional barcodes, QR codes can store more information in a smaller space, including URLs, text, phone numbers, WiFi passwords, and more. Today, QR codes are widely used in mobile payments, advertising and marketing, product tracing, identity verification, and many other fields.

Standard QR codes can store up to 7,089 numeric characters or 4,296 alphanumeric characters. Through error correction, QR codes can still be correctly scanned even when partially damaged or obscured.

How to Use This Tool?

  1. Enter text to encode in the input box (URLs, text, contact info, etc.)
  2. Select QR code image size (200px to 500px)
  3. Select error correction level (default "Medium 15%" recommended)
  4. Click the "Generate QR Code" button
  5. After generation, click the "Download" button to save as PNG image

Error Correction Levels

  • Low (Level L): About 7% of data can be recovered. Suitable for scenarios with limited space and clean environments.
  • Medium (Level M): About 15% of data can be recovered. Recommended for daily use, balancing capacity and reliability.
  • High (Level Q): About 25% of data can be recovered. Suitable for scenarios where a Logo overlay may be added.
  • Highest (Level H): About 30% of data can be recovered. Suitable for industrial environments or when a Logo needs to be placed in the center.

Common Use Cases

  • URL Sharing: Convert website links to QR codes for easy scanning
  • Business Cards: Encode contact information as a QR code on business cards
  • WiFi Sharing: Encode WiFi name and password as a QR code
  • Product Labels: Generate traceability QR codes for products
  • Event Check-in: Generate event entry QR codes

FAQ

Q: Is there a length limit for QR code content?

Yes. The longer the content, the denser the QR code and the harder it is to scan. We recommend using URL shorteners for links. Non-ASCII characters (such as Chinese) also take up more space.

Q: Are the generated QR codes secure?

This tool generates QR codes entirely in your browser locally with no server transmission. However, note that QR codes are public information — do not encode sensitive data (like passwords) directly.

Timestamp ConverterTools

Convert between timestamps and readable dates

Current timestamp: ...

Timestamp ConverterTools — Tutorial

What is a Unix Timestamp?

A Unix Timestamp is the total number of seconds elapsed since January 1, 1970 00:00:00 UTC (Unix Epoch). It is the most universal time representation in computer systems, timezone-independent, and easy to calculate and compare. Almost all programming languages and databases natively support timestamps.

Two common timestamp precisions:

  • Second-level timestamp: 10 digits, e.g. 1712000000. Most systems use second-level precision by default.
  • Millisecond-level timestamp: 13 digits, e.g. 1712000000000. JavaScript's Date.now() returns millisecond-level timestamps.

How to Use This Tool?

  1. Timestamp to Date: Enter a timestamp number in the input box and click the "Timestamp to Date" button. The tool will automatically detect whether it is in seconds or milliseconds.
  2. Date to Timestamp: Enter a date string (e.g. 2026-01-15 or 2026-01-15T10:30:00) and click the "Date to Timestamp" button.
  3. Get Current Timestamp: Click the "Current Timestamp" button to quickly fill in the current timestamp.
  4. The top of the page displays the current timestamp in real-time for easy reference

Common Use Cases

  • Database Debugging: Convert timestamps stored in databases to readable dates
  • API Development: Quickly get the current timestamp for API testing
  • Log Analysis: Convert timestamps in server logs to local time
  • Frontend Development: Convert between JavaScript timestamps and backend time formats
  • Scheduled Tasks: Calculate timestamps for specific dates to configure cron jobs

FAQ

Q: Will timestamps overflow?

32-bit signed integer seconds timestamps will overflow on January 19, 2038 (the famous "Year 2038 problem"). However, modern systems generally use 64-bit integers, and this issue has been resolved on most platforms.

Q: What timezone does the tool display?

The tool displays both local time and UTC time for easy comparison. Timestamps are UTC-standard and do not contain timezone information.

URL Encoder/DecoderTools

URL encoding and decoding conversion

URL Encoder/DecoderTools — Tutorial

What is URL Encoding?

URL encoding (also known as percent-encoding) is the process of converting characters that are not allowed in URLs into the %XX format. According to the RFC 3986 specification, only a subset of ASCII characters (letters, digits, and a few special symbols) are allowed in URLs. Other characters (such as non-ASCII text, spaces, and special symbols) must be encoded for safe transmission.

For example, the text "hello world" with a space becomes hello%20world after URL encoding, and the space becomes %20 or +. This is a fundamental and essential encoding mechanism in web development.

encodeURIComponent vs. encodeURI

JavaScript provides two URL encoding functions for different scenarios:

  • encodeURIComponent: Encodes all special characters (including /, ?, &, =, etc.). Suitable for encoding URL parameter values, e.g.: ?q=encodeURIComponent(value)
  • encodeURI: Preserves URL structural characters (/, ?, #, &, =, etc.). Suitable for encoding complete URLs, e.g.: encodeURI(fullURL)

How to Use This Tool?

  1. Enter the text to encode or decode in the input box
  2. Select the corresponding action button:
    • encodeURIComponent — Encode URL parameter values (recommended)
    • decodeURIComponent — Decode URL parameter values
    • encodeURI — Encode complete URLs
    • decodeURI — Decode complete URLs
  3. The result will appear in the output box and can be copied with one click

Common Use Cases

  • API Debugging: Encode request parameters containing special characters
  • URL Parsing: Decode encoded URLs from the browser address bar into readable text
  • Web Scraping: Properly encode non-ASCII links in scraping targets
  • Frontend-Backend Integration: Troubleshoot parameter passing issues caused by inconsistent URL encoding

FAQ

Q: Why does the encoded text become so long?

In UTF-8 encoding, a single non-ASCII character takes up 3 bytes, and each byte is encoded as %XX (3 characters), so one non-ASCII character becomes 9 characters after encoding. This is normal behavior.

Base64 Encoder/DecoderTools

Base64 encoding and decoding, supports Unicode

Base64 Encoder/DecoderTools — Tutorial

What is Base64 Encoding?

Base64 is an encoding method that represents binary data using 64 printable characters (A-Z, a-z, 0-9, +, /). It divides every 3 bytes (24 bits) of data into 4 groups of 6 bits each, mapping each group to a printable character. The encoded data is approximately 33% larger than the original data.

Base64 was originally designed for transmitting binary attachments (such as images and files) in email systems, because early email systems could only handle ASCII text. Today, Base64 is widely used throughout web development.

Common Use Cases

  • Data URLs: Embed small images directly in HTML or CSS, e.g. data:image/png;base64,iVBOR...
  • HTTP Authentication: Basic Auth uses Base64 to encode usernames and passwords
  • JWT Tokens: JSON Web Token's Header and Payload use Base64 encoding
  • Email Attachments: Encoding and transmitting attachments in the MIME protocol
  • Config Files: Safely store binary data in environment variables or configuration files
  • API Data Transfer: Transmit binary data through JSON/XML interfaces

How to Use This Tool?

  1. Encode: Enter any text in the input box (supports Unicode characters) and click "Base64 Encode"
  2. Decode: Paste a Base64 string in the input box and click "Base64 Decode"
  3. The result will appear in the output box. Click the "Copy" button to use it

Characteristics of Base64 Encoding

Base64 is an encoding method, not encryption. Anyone can easily decode Base64 content, so it should never be used to protect sensitive data. If secure transmission is needed, use real encryption algorithms such as AES or RSA. Base64's purpose is solely to convert binary data into text format for transmission over text-based protocols.

FAQ

Q: Does it support non-ASCII characters?

Yes. This tool uses UTF-8 encoding to handle all Unicode characters, ensuring compatibility with other standard tools.

Q: Why are there equal signs at the end of Base64 encoded text?

The equal sign = is a padding character. Because Base64 converts 3 bytes into 4 characters, when the original data length is not a multiple of 3, 1 or 2 = signs are appended at the end for alignment.

Hash GeneratorTools

Generate MD5, SHA-1, SHA-256, SHA-512 hash values

Hash GeneratorTools — Tutorial

What is a Hash?

A hash (also known as a digest or checksum) is a one-way cryptographic function that converts input data of arbitrary length into a fixed-length output string. This output is called a "hash value" or "message digest." Hash functions have the following core properties:

  • Deterministic: The same input always produces the same output
  • Irreversible: It is impossible to derive the original data from the hash value
  • Avalanche Effect: A tiny change in input data produces a completely different hash value
  • Collision Resistant: It is practically impossible to find two different inputs that produce the same hash value

Supported Hash Algorithms

  • MD5: Produces a 128-bit (32 hex character) hash value. Fast, but known security vulnerabilities have been found. Not recommended for security purposes. Still widely used for non-security purposes like file checksums and cache keys.
  • SHA-1: Produces a 160-bit (40 character) hash value. Proven to be vulnerable to collision attacks. Not recommended for security purposes, but still used in some legacy systems.
  • SHA-256: Produces a 256-bit (64 character) hash value. A member of the SHA-2 family, currently the most widely used secure hash algorithm. Recommended for security scenarios such as password storage, digital signatures, and blockchain.
  • SHA-512: Produces a 512-bit (128 character) hash value. The highest security level in the SHA-2 family, suitable for scenarios requiring the utmost security. Longer output and slightly more computationally intensive.

How to Use This Tool?

  1. Enter the text to compute a hash value in the input box
  2. Click the corresponding algorithm button (MD5, SHA-1, SHA-256, SHA-512)
  3. Hash values appear immediately in the output area
  4. Click the "Copy" button to copy the hash value

Common Use Cases

  • File Verification: Verify that downloaded files are complete and unmodified
  • Password Storage: Store hash values of passwords in databases instead of plaintext
  • Data Deduplication: Compare hash values to determine if two datasets are identical
  • Digital Signatures: Generate hash values for documents or messages to verify identity
  • Git Version Control: Uses SHA-1 to identify each commit
  • Blockchain: Bitcoin uses SHA-256, Ethereum uses Keccak-256

FAQ

Q: Is MD5 still secure?

MD5 was proven to have collision vulnerabilities in 2004 and should no longer be used for security-sensitive scenarios (such as password storage or digital signatures). However, it is still appropriate for non-security purposes (like file cache keys or data deduplication). For security scenarios, please use SHA-256 or stronger algorithms.

Q: Can hash values be decrypted?

No. Hashes are one-way functions and are irreversible by design. The only way to verify if data matches is to recompute the hash and compare. This is exactly how hashes are used for password storage: the system stores the hash of the password, and upon login, recalculates and compares with the stored value.