Koaris Tools — Free Online Tools for Developers & Marketers

Media

Paint Online

Draw, add text and sketch AI references in your browser. Download your drawing as a PNG or copy the image to paste elsewhere.

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Marketing

Email Signature Generator

Create an HTML email signature with contact details, brand colors and an optional logo, then copy or download it.

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Media

Image Converter

Convert images to PNG, JPEG or WebP in your browser, preview the result and download it.

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Media

Image Resizer

Resize images in your browser by percentage or exact dimensions, then download the result.

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Encoders & Formatters

Markdown Converter

Convert documents, data, rich text, and public webpages into editable Markdown.

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Marketing

OG Preview Checker

Inspect a public URL’s sharing metadata and approximate Facebook, LinkedIn, X, and WhatsApp previews.

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Marketing

Meta Tag Generator

Generate SEO meta tags, Open Graph and Twitter Card tags with live Google and social previews.

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Encoders & Formatters

URL Encoder & Decoder

Percent-encode text for safe URLs, or decode an encoded string back to readable text.

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Encoders & Formatters

Base64 Encoder & Decoder

Encode text and images to Base64, or decode a Base64 string back to its original form.

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Encoders & Formatters

HTML Text Encoder & Decoder

Turn special characters into HTML entities so they render literally — or decode entities back to text.

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Encoders & Formatters

HTML Beautifier

Reindent and tidy messy or minified HTML so it is readable again.

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Productivity

Pomodoro Timer

Focus in 25-minute blocks with short breaks, and track how many you complete.

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Generators

QR Code Generator

Make a QR code for a link, text, Wi-Fi network, email, phone number, SMS or contact card, and download it as SVG or a high-resolution PNG.

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Marketing

WhatsApp Link Generator (wa.me)

Build a wa.me link that opens a chat with your number and an optional pre-filled message.

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Marketing

UTM Generator & Builder

Free UTM generator, builder and campaign URL creator: tag any link with utm_source, utm_medium and utm_campaign so analytics attributes every click.

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Generators

Mailto Link Generator

Build a mailto: link with recipient, subject, body, CC and BCC already filled in.

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Media

Image Compressor

Shrink JPG, PNG, WebP or GIF images in your browser, one or many at once, and compare before downloading.

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Media

Image to SVG Converter

Convert JPG, PNG, and WebP images into clean, scalable SVG vector graphics or embedded vector wrappers in your browser.

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Media

Background Remover

Cut the background out of a photo in your browser and download it as a transparent PNG.

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Generators

Favicon Generator

Turn one image or SVG into a complete favicon set, including a real multi-size favicon.ico, a maskable Android icon and the matching <head> markup.

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Media

Screen Streamer

Share your screen live with anyone via private peer-to-peer WebRTC link, or record client-side.

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Marketing

SEO & GEO Analyzer

Enter a URL for weighted SEO and GEO diagnostics covering search, crawler access, and AI-readable structure.

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Generators

Cron Expression Generator

Build a cron schedule expression with a visual editor, or explain any existing cron string in plain English.

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Encoders & Formatters

JSON Formatter & Validator

Pretty-print, validate, and minify JSON — with syntax coloring and instant error reporting.

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Generators

Password Generator

Generate strong, random passwords in your browser using cryptographic randomness — nothing is ever sent to a server.

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Media

Color Picker & Palette

Pick a color and convert it between HEX, RGB, and HSL — then generate complementary, triadic, or analogous palettes.

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Productivity

Word Counter

Count words, characters, sentences, and paragraphs — and see reading time — live as you type.

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Encoders & Formatters

Markdown to HTML

Convert Markdown to clean HTML and preview the rendered output — live, in your browser.

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Encoders & Formatters

Regex Tester

Write a regular expression and test it against sample text live — with match highlighting, capture group labels, and flag toggles.

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Productivity

Text & PDF Compare

Compare two texts or files — PDF, DOCX, TXT, CSV, JSON — and see every added, removed and changed line or word. Runs in your browser.

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Media

MP4 Player

Play MP4 videos right in your browser with speed control, looping, picture-in-picture and full screen — no uploads.

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Productivity

Raffle Picker

Draw random winners from a pasted list, with an optional countdown and a confetti celebration.

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Productivity

ATS Resume Checker

Upload your PDF or DOCX résumé and get a free ATS score from 0 to 100, with a pass/fail check and a fix for every criterion.

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