Free Online Conversion Tools | curl to Code, JSON to Struct, Power, Color & More

All Conversion Tools

A curated collection of 28 free conversion utilities. Every tool runs entirely in your browser — no data is ever sent to a server.

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Which Conversion Tool Do You Need?

Tool	Converts	Common Use
Base64 Encoder	Text ↔ Base64	Embed images in HTML/CSS, API auth headers
Base32 Encoder	Text ↔ Base32	OTP secrets, human-readable encoding
URL Encoder	Text ↔ URL-safe	Query strings, percent-encoding
UTF-8 Encoder	Text → UTF-8 bytes	Character encoding debugging
UTF-8 Decoder	UTF-8 bytes → Text	Reverse encoding, data recovery
Unicode Converter	Text ↔ Unicode	Escape sequences, emoji codes
Morse Code	Text ↔ Morse	Learning, hobby radio, puzzles
File to Base64	File → Base64 string	Inline file embedding, data URIs
Base64 to File	Base64 string → File	Download embedded files, decode attachments
Chinese Converter	Simplified ↔ Traditional	Cross-region Chinese communication
Unix Timestamp	Timestamp ↔ Date	Debug logs, API development, cron jobs
GB2312 Table	GB2312 codes ↔ Characters	Chinese encoding reference, legacy systems
HTML to Markdown	HTML ↔ Markdown	Content migration, documentation, blogging
Rich Text to Markdown	WYSIWYG HTML → Markdown	TinyMCE, CKEditor, Quill, WordPress exports
Speed Converter	13 speed units	mph to km/h, knots, mach, speed of light
CSV to HTML Table	CSV → HTML table	Data publishing, spreadsheet embedding
Case Converter	10 text case formats	snake_case, camelCase, PascalCase, UPPER/lower
Length Converter	19 length units, 4 systems	km to miles, meters to feet, Li to km, Chi to inches
Weight Converter	21 weight units, 5 systems	kg to lbs, jin to kg, stone, tael to ounces
Area Converter	19 area units, 4 systems	acres to hectares, mu to acres, tsubo to sq ft
Volume Converter	24 volume units, 6 systems	US vs UK gallons, dou to liters, cooking measures
Angle Converter	15 angle units, 5 categories	degrees to radians, NATO vs Soviet mils, MOA
File Size Converter	11 units, decimal & binary	bytes to MB, GB vs GiB, why 1TB=931GB
Power Converter	11 units, 4 categories	hp to kW, 3 horsepower types, BTU/h, ton of AC
Pressure Converter	14 units, 4 categories	psi to bar, tire/weather/diving/medical scenarios
JSON to Struct	JSON → 4 languages	Go struct, TypeScript interface, Python dataclass, Java
Color Converter	5 color formats	HEX, RGB, HSL, HSV, CMYK — live preview
curl to Code	curl → 5 languages	Python, Go, Java, PHP, Node.js code generation

What Are Online Conversion Tools?

Conversion tools transform data from one format to another — encoding text as Base64, converting Unicode characters to their numeric codes, translating timestamps into readable dates, or switching between character sets. Developers use them daily for debugging, data processing, and API integration. Non-developers use them too: converting files to Base64 for email attachments, translating Morse code for learning, or converting between Simplified and Traditional Chinese.

Why Client-Side Conversion Matters

All PureAINav conversion tools run entirely in your browser using JavaScript. This means your data never leaves your device. When you paste a password into the Base64 encoder or convert a confidential file, nothing is transmitted to a server. This is especially important for conversion tools — many online converters silently upload your data to their servers for processing, creating a privacy risk. With client-side tools, the conversion happens instantly and privately on your machine.

Encoding vs Encryption — Know the Difference

A common misconception: encoding is not encryption. Base64, URL encoding, and UTF-8 are encoding schemes — they transform data into different representations that are fully reversible without any key. Anyone can decode a Base64 string back to its original form. Encryption (like AES or RSA) scrambles data so it can only be read with a decryption key. Use encoding for data format compatibility; use encryption for security.

Frequently Asked Questions

Which tool should I use to convert a file to Base64?

Use the File to Base64 tool. Upload any file and get a Base64-encoded string instantly. This is useful for embedding images directly in HTML or CSS, or attaching binary files in JSON APIs. The reverse operation is available via Base64 to File.

What is the difference between Base64, Base32, and URL encoding?

Base64 uses 64 characters (A-Z, a-z, 0-9, +, /) and is the most common binary-to-text encoding. Base32 uses 32 characters (A-Z, 2-7) — it produces longer output but is easier for humans to read and type (no confusing characters like 1/l/I or 0/O). URL encoding (percent-encoding) converts special characters into %XX format for safe use in URLs.

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

Use the Unix Timestamp Converter. Paste any Unix timestamp (e.g., 1781000000) and instantly see it as ISO 8601, RFC 2822, UTC, and local time formats. You can also convert dates back to timestamps.

Can I convert between Simplified and Traditional Chinese?

Yes. The Chinese Converter switches between Simplified (简体) and Traditional (繁體) Chinese characters. This is useful for reading content from different Chinese-speaking regions.

Are these conversion tools safe for sensitive data?

Yes. All 28 conversion tools run entirely in your browser — your data is processed locally and never sent to any server. No signup, no tracking, no data collection. You can verify this by disconnecting from the internet after the page loads — all tools continue working offline.

Can I convert between Chinese traditional length units and metric?

Yes. The Length Converter supports 19 length units across 4 measurement systems including Chinese traditional units — Li (里), Zhang (丈), Chi (尺), Cun (寸), Fen (分), and Li-milli (厘). Enter any value and see metric, imperial, Chinese, and nautical equivalents instantly.

Can I convert Chinese jin (斤) and liang (两) to pounds and ounces?

Yes. The Weight Converter covers 21 units including PRC jin (500g), Taiwan jin (600g), and Hong Kong catty (604.8g), plus liang/tael, qian/mace, stone, troy ounce, and carat. It's the only converter showing all three regional jin variants side by side.

How do I convert Chinese mu (亩) or Japanese tsubo (坪) to acres?

Use the Area Converter — 1 mu = 0.1647 acres, 1 tsubo = 35.58 sq ft. It covers 19 area units across Metric, Imperial, Chinese (mu/qing/fen), and Japanese/Taiwanese (tsubo/se/chia) systems in one real-time grid.

What is the difference between US and UK gallons, pints, and fluid ounces?

The Volume Converter shows US and UK units side by side. US gallon = 3.785 L; UK gallon = 4.546 L (20% larger). This matters for recipes, fuel economy, and international product labels. The converter also includes Chinese dou/sheng and Japanese sake measures (go/sho).

Can I convert curl commands to Python, Go, or Java code?

Yes. The curl to Code Converter parses curl commands and generates working code in 5 languages: Python (requests), Go (net/http), Java (HttpClient), PHP (cURL), and Node.js (fetch). Paste a curl command from your terminal or browser DevTools and get all 5 implementations instantly.

How do NATO mils differ from Soviet mils and milliradians?

The Angle Converter shows all three military mil systems side by side: NATO (6400/circle), Soviet (6000/circle), and true milliradians (6283/circle). It also covers MOA for shooters, gradians for surveyors, and navigation units.

What is Morse code and how do I use it?

Morse code encodes letters and numbers as sequences of dots (.) and dashes (-). The Morse Code tool converts text to Morse and Morse back to text. It also supports audio playback of Morse signals for learning and practice.