HashmiTools provides a complete toolkit for developers and programmers. Format and validate JSON, encode/decode Base64 strings, encode/decode URLs, generate secure passwords, create QR codes, convert HEX to RGB colors, test regex patterns, and preview Markdown — all in your browser with no sign-up required.
Frequently Asked Questions
Yes, all developer tools on HashmiTools are 100% free with no usage limits or sign-up required.
Base64 is an encoding scheme, not encryption. It is reversible and should not be used to secure sensitive data.
Currently the QR Code Generator creates one code at a time with customization options. Batch generation is on our roadmap.
Developer Tools — Free Browser-Based Utilities for Programmers
Every developer maintains a personal toolkit of small utilities they reach for constantly: a quick JSON formatter to make sense of an API response, a Base64 encoder/decoder for debugging JWT tokens, a color picker to grab a hex value, a URL encoder for safe query string construction. These tasks are trivial but genuinely time-consuming when they require opening a separate app, running a script, or fighting with command-line flags.
HashmiTools' Developer section puts these utilities in the browser — always available, no installation, no account. Every tool runs client-side so your data stays on your device. This matters for developers working with sensitive keys, tokens, credentials, or proprietary API responses that shouldn't be sent to unknown third-party servers.
Tools in This Section
{ } JSON Formatter
Paste any JSON to format, validate, and syntax-highlight it. Minify mode for production, expand/collapse tree view for exploration.
🔒 Base64 Encoder/Decoder
Encode text or binary files to Base64. Decode Base64 strings including JWT payloads and data URIs.
🔗 URL Encoder/Decoder
Percent-encode special characters for safe URL usage. Decode encoded URLs to readable format.
🎨 HEX/RGB Converter
Convert between HEX, RGB, HSL, and RGBA colour formats. Live preview of the selected colour.
🔑 Password Generator
Cryptographically strong password generation with configurable length, character sets, and strength indicator.
📊 SEO Audit Tool
Paste HTML source for on-page SEO analysis: meta tags, heading structure, keyword density, canonical tags, schema markup.
Why Client-Side Processing Matters for Developers
Most online developer tools send your input to their servers to process. For developers, this creates real security risks:
API keys and tokens — pasting a production API key into an online formatter that logs inputs could expose your entire backend
Customer data — debugging JSON that contains user information by sending it to a third-party tool may violate your privacy policy or GDPR/PDPA obligations
Proprietary code and configuration — database connection strings, environment variables, and internal API schemas should not leave your network
Every tool in this section processes your data entirely in your browser using JavaScript. Nothing is transmitted to HashmiTools or any third party. You can verify this by disconnecting from the internet after the page loads — the tools continue to work.
Who Uses These Tools
Full-stack developers debugging API responses and request/response bodies during development
Frontend developers converting colour formats for CSS, generating test passwords, and encoding URL parameters
Computer science students learning how encoding schemes work by experimenting with real examples
QA testers constructing test inputs, decoding responses, and auditing page structure
Frequently Asked Questions
Is it safe to paste API keys into the Base64 or JSON tools?
Yes — all tools on this page process data client-side in your browser. No data is sent to our servers. However, as general security hygiene, avoid pasting production secrets into any browser tool you haven't verified. After use, clear the input field and use Ctrl+Shift+Delete to clear browser memory if working with highly sensitive credentials.
Do these tools work offline?
Yes, once the page is loaded. Since all processing is JavaScript running in your browser, these tools continue to work without an internet connection after initial page load. The one exception is the Currency Converter, which fetches live rates and requires connectivity for rate updates.
Is there a size limit for the JSON Formatter?
The JSON Formatter handles files up to approximately 5 MB in the browser before performance degrades noticeably. For very large JSON files (10 MB+), command-line tools like jq or browser DevTools' JSON viewer are more appropriate. For typical API debugging (responses under 1 MB), the browser tool is fast and convenient.
Are more developer tools planned?
Yes — a regex tester with live match highlighting, a cron expression builder, a diff tool for comparing two text blocks, and a timestamp converter (Unix/ISO/human-readable) are in development. Tool additions are prioritised based on user requests — use the contact form to suggest what you need.
Can I use these tools in a corporate environment?
Since tools run client-side with no server data transmission, they are suitable for most corporate environments. However, always check your company's acceptable use policy for browser-based tools. If you need a self-hosted version for internal use in an enterprise environment, contact us through the contact form.
How This Works — Developer Tools That Work Entirely in Your Browser
HashmiTools Developer Tools is a curated collection of utilities for web developers, software engineers, and technical users who need reliable, fast tools without installing software or pasting sensitive code into unfamiliar services. Every tool in this section runs entirely client-side in your browser — your code, JSON, Base64 strings, and URL parameters never leave your device.
The collection includes: a JSON Formatter and Validator that instantly prettifies and validates JSON with syntax highlighting and error reporting; a Base64 Encoder/Decoder for encoding binary data and debugging API payloads; a URL Encoder/Decoder for encoding query strings and decoding percent-encoded URLs; an HEX/RGB Color Converter for designers working between design tools and CSS; a Password Generator with configurable length, character sets, and strength scoring; an SEO Audit tool that analyses any URL for on-page SEO issues; a QR Code Generator that creates scannable QR codes for URLs, text, and contact information; and a YouTube SEO Optimizer for video creators.
How to use Developer Tools: Each tool is accessible via its own tab in this hub or directly from the tool cards above. All tools load instantly, work offline after the initial page load, and produce results you can copy to clipboard with a single click. No account, no API key, and no file uploads required for any tool in this section.
Frequently Asked Questions
Are these developer tools safe to use with sensitive code or credentials?
All tools in the Developer section process data locally in your browser. Your JSON, Base64 strings, passwords, and URLs are never transmitted to HashmiTools servers or any third party. The Password Generator, in particular, uses the browser's cryptographically secure random number generator (window.crypto.getRandomValues) rather than Math.random(), making generated passwords genuinely secure. That said, as a general security practice, avoid pasting production database credentials, API secrets, or private keys into any web-based tool — use local command-line tools for handling the most sensitive materials.
How is the JSON Formatter different from JSONLint or other validators?
The HashmiTools JSON Formatter combines validation, prettification, and minification in a single interface with no ads interrupting your workflow. It highlights the exact location of syntax errors, supports nested object collapsing for large JSON structures, and formats output with configurable indentation (2-space or 4-space). It handles very large JSON payloads (multi-megabyte API responses) more gracefully than some online alternatives because processing is entirely client-side with no upload timeout. For developers debugging API responses in a hurry, the instant feedback on validation errors saves significant time.
Can I use the QR Generator for business cards or print materials?
Yes. The QR Generator produces SVG and high-resolution PNG QR codes suitable for print. For business card use, generate the QR code at the highest available resolution setting, download as PNG, and use at a minimum print size of 2cm × 2cm. QR codes smaller than 2cm × 2cm may fail to scan reliably on some smartphone cameras. Always test-scan your generated QR code before sending files to print. The tool supports URL, plain text, email, phone number, and SMS QR code types.
What is Base64 encoding and when do I need it as a developer?
Base64 is an encoding scheme that converts binary data (images, files, binary API payloads) into a string of printable ASCII characters. Developers need it when: embedding small images directly in HTML or CSS as data URIs (avoiding an extra HTTP request); handling API authentication headers (Basic Auth sends credentials as Base64-encoded "username:password"); debugging JWT tokens (which are Base64-encoded JSON); and processing binary file uploads in web applications. The HashmiTools Base64 Encoder/Decoder supports both encoding any text to Base64 and decoding Base64 strings back to their original form, with URL-safe Base64 variant support.