Developer Utilities & Tools
33 tools in this collection — free, instant, and private in your browser.
Developer utilities are browser-based tools that handle the small but repetitive tasks that come up constantly in software development: formatting data, converting between encodings, generating boilerplate code, and building configuration strings. Having them available in a browser tab means you can reach them from any machine without configuring a local environment.
Data and encoding tools cover a wide range of everyday needs. The Base64 file encoder converts binary files or text to Base64 for embedding in JSON payloads or data URIs. The HTML entity encoder and decoder handles the escape sequences required for safe HTML output. Backslash escape and unescape utilities are useful when working with strings in programming languages that use backslash as an escape character, or when reading log output that has been over-escaped.
Code generation tools speed up setup work. The CSV to SQL INSERT generator turns a spreadsheet into ready-to-run database statements. The cron builder and cron expression explainer work as a pair: build a schedule visually and see the next run times, or paste an existing cron string and get a plain-English explanation. The CSS generators for gradients, box shadows, border radii, and clip paths let you tune visual properties interactively and copy the resulting CSS without writing it from scratch.
Identification and hashing tools round out the category. The bulk UUID generator creates as many version-4 UUIDs as you need in one step. The file hash generator computes MD5, SHA-1, or SHA-256 checksums client-side for integrity verification. The HMAC generator produces keyed message authentication codes for testing API signatures. The character map lets you browse and copy Unicode characters by name or code point.
Choose the specific tool that matches your immediate task. For one-off needs, the browser-based versions are faster than installing a package or writing a script; for repeated use, many of them accept paste-in input that makes them just as quick as a command-line alias.
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| Tool | What it does |
|---|---|
| Backslash Escape / Unescape | Escape or unescape backslash sequences (\n, \t, \r, \", \\) in any string. Runs entirely in your browser. |
| Barcode Generator | Generate Code-128 barcodes from any text in your browser and download them as PNG. No libraries, no uploads. |
| Base64 File Encoder | Encode any file to Base64 or a data URI directly in your browser. Your file is never uploaded. |
| Bulk UUID Generator | Generate up to 1000 UUIDs (v4) at once using crypto.randomUUID. Copy or download as a text file. |
| CSS Border-Radius Generator | Shape each corner with independent border-radius sliders and a live preview. Copy the CSS — supports % and px units. |
| CSS Box-Shadow Generator | Design CSS box-shadows with sliders for offset, blur, spread, color and opacity. Live preview and one-click copy. |
| CSS Clip-Path Maker | Generate CSS clip-path shapes from presets (triangle, star, hexagon, arrow and more) with a live preview. Copy the CSS. |
| CSS Gradient Generator | Build linear and radial CSS gradients with live preview, adjustable angle, colors and stops. Copy the CSS instantly. |
| CSV to SQL INSERT Generator | Turn a CSV into SQL INSERT statements for any table name, with automatic number/boolean detection and quoting. |
| Case Converter Studio | Convert text between six cases — UPPER, lower, Title Case, camelCase, snake_case, and kebab-case — with one click. Free and private. |
| Character Map | Browse Unicode character blocks — ASCII, Latin, Greek, Cyrillic, symbols, emoji and more. Click a character to collect it, then copy. Runs in your browser. |
| Cron Builder with Next-Run Preview | Build a cron expression with dropdowns or by hand, get a plain-English description, and preview the next 10 run times in any timezone. |
| Cron Expression Explainer | Translate any cron expression into plain English instantly. Supports 5-field and 6-field formats. |
| File Hash Generator | Hash text or files with SHA-1, SHA-256, or SHA-512 directly in your browser. Nothing is uploaded. |
| Find and Replace with Regex | Find and replace text using full regular-expression patterns with flags. Supports global, case-insensitive, and multiline modes. Runs in your browser. |
| HMAC Generator | Compute HMAC-SHA-256 or HMAC-SHA-512 signatures in your browser. Your key and message stay on your device. |
| HTML Entity Encoder / Decoder | Encode special characters to HTML entities or decode entities back to plain text, entirely in your browser. |
| ICS Calendar Event Generator | Create a calendar event and download a standard .ics (iCalendar) file you can add to Google Calendar, Outlook, or Apple Calendar. All in your browser. |
| JSON Formatter & Validator | Format, validate, and minify JSON in your browser. Pretty-print with 2/4 spaces or tabs, or minify. Nothing uploaded. |
| JSON Minify / Beautify | Pretty-print JSON with configurable indentation, or minify it to a single compact line. Runs in your browser. |
| JSON to SQL INSERT Generator | Convert a JSON array of objects into SQL INSERT statements. The union of all keys becomes the column list. |
| JSON to TypeScript Interface | Infer TypeScript interfaces from any JSON object, with nested objects and array element types. Runs in your browser. |
| Lorem Ipsum Generator | Generate Lorem Ipsum placeholder text with a configurable number of paragraphs and words. Instant, free, no signup. |
| Markdown Editor | Write Markdown with a live preview and download as .md or .html. Runs entirely in your browser — nothing is uploaded. |
| Markdown Table Generator | Build Markdown tables visually: set rows and columns, type into the grid, and copy the output. Free, instant, no upload. |
| Markdown to HTML Converter | Convert Markdown to clean, XSS-safe HTML with a live preview. Powered by marked and sanitized with DOMPurify. Download a standalone .html file. All in your browser. |
| Mesh Gradient Generator | Generate vibrant CSS mesh gradients built from layered radial gradients. Randomize and copy the CSS — no images needed. |
| Password Generator Pro | Generate strong, random passwords with configurable length and character sets. Shows entropy in bits. Uses crypto.getRandomValues — nothing is uploaded. |
| Query String Parser | Parse any URL or query string into a table of key-value pairs. Handles repeated keys, plus-encoding and percent-encoding. |
| Regex Railroad Diagram Visualizer | Visualize any regex as a railroad/flow diagram with live match highlighting, capture groups, and g/i/m/s flag toggles. Runs entirely in your browser. |
| Regex Tester | Test regular expressions against any string with live match highlighting. All processing is in-browser. |
| URL Encoder / Decoder | Encode or decode URLs and URI components live in your browser. Supports encodeURI and encodeURIComponent. |
| vCard Generator | Fill in contact details and download a standard vCard (.vcf) file you can import into any phone or address book. Runs entirely in your browser. |
Frequently asked questions
- Are file hashes computed locally or uploaded to a server?
- All hashing is done entirely in your browser using the Web Crypto API or a JavaScript implementation. Your files are never uploaded. You can verify this by disconnecting from the internet and retrying — the tool continues to work.
- What is the difference between the Cron Builder and the Cron Expression Explainer?
- The Cron Builder starts from a human-readable schedule (every weekday at 9 AM, for example) and generates the correct cron expression plus a preview of the next several run times. The Cron Expression Explainer goes the other direction: you paste an existing cron string and it tells you in plain English when it will fire.
- Can I use the CSS generators for production code?
- Yes. The output is standard CSS that works in all modern browsers. Copy it directly into your stylesheet. For older browser support you may want to add vendor prefixes manually, but for clip-path, gradients, and box shadows, unprefixed CSS is now broadly supported.