Add Line Numbers - Online Number Text Lines Tool
Number each line of your text sequentially. Customize start number and format. Useful for code snippets, tutorials, and document review. Private operation.
UD5 Toolkit
Instantly convert between square feet, acres, hectares, square meters, square yards, square miles and square kilometers. Trusted by real‑estate professionals, farmers, and surveyors worldwide.
Number each line of your text sequentially. Customize start number and format. Useful for code snippets, tutorials, and document review. Private operation.
Generate cryptographic key pairs using the Web Crypto API. Export as JWK or raw. No server needed; pure security.
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds. Ideal for developers debugging time-related code.
Convert an SVG shape into a CSS mask‑image. Transparent regions become masked. Great for custom image crops. Client‑side.
Fill in container image and ports. Generate a Deployment and Service YAML with best practices. Start your K8s journey.
Upload a photo to create a numbered painting canvas with color swatches. Print and paint. Local only.
Convert JSON data structures to clean, human-readable YAML. Indentation and formatting preserved. All processing done locally for your privacy.
Record audio from your microphone and export as a WAV file. Monitor levels. Processed entirely in your browser.
Record audio from your microphone and export as a WAV file. Monitor levels. Processed entirely in your browser.
Convert any human‑readable date to a Unix timestamp in seconds or milliseconds. Also shows ISO 8601. Clean interface.
Generate custom placeholder images for mockups and layouts. Specify dimensions, colors, and text. Export as PNG or use the generated data URI. Entirely browser-based.
Generate random license keys or serial numbers in various formats (XXXX-XXXX-XXXX). Useful for software activation testing. Local generation.
Generate classic retro sound effects (coin, jump, explosion) using oscillators and noise. Play and download as WAV. Web Audio API fun.
Paste a phone number and format it according to the E.164 standard. Identify country and detect common typos. Local parser.
An animated hourglass that you can set for any time. Watch the sand flow. Beautiful and calming timer.
Dual-function tool: a precise stopwatch with laps and a configurable countdown timer with alarm sound. Works offline, perfect for activities.
Paste start and end SVG paths with the same number of points and preview a smooth morph animation. Copy SMIL code.
Upload multiple SVGs and combine them into a single SVG sprite sheet with `<symbol>` and `<use>`. Fast icon system.
Write HTML, CSS, and JavaScript in separate panes and see the result in real time. Store your snippets locally.
Generate the next sequential invoice number with optional prefix and date stamp. Keep track locally or export.
Paste a list of URLs or texts and generate QR codes all at once. Download as individual images or a single sheet.
Flip images vertically or horizontally, and rotate in 90° increments. Quick and simple editing right in the browser. Download the corrected image instantly.
Combine random character, setting, conflict, and genre to generate unique story prompts. Over 10,000 possible combinations. Perfect for overcoming writer's block.
Get a clean, commented JS plugin skeleton with IIFE or ES module pattern. Start your new library faster.
Adjust opacity visually with a slider and see the different CSS representations (opacity property vs RGBA/HSLA). Copy best option.
Generate a subtle or heavy noise/grain texture as a CSS background. Adjust intensity and color. Copy the small code.
Compare visibility: hidden vs display: none. See how each affects layout and event listeners. Inline code.
View the individual red, green, and blue channels of an image as grayscale. Photographer and developer tool.
Generate a grey placeholder image with custom text and dimensions. Data URI output. No external service.
Use the <template> tag to hold hidden HTML that is cloned and injected by JavaScript. Common pattern.