A free browser-based WebP / AVIF / PNG / JPEG image conversion tool. It offers fast conversion while protecting privacy, without uploading images to a server. Supports image quality adjustment, batch download, Before/After comparison slider, and Base64 export.

Simulate OGP display in real-time on major social media platforms such as X (Twitter), Facebook, LINE, Slack, and Discord. Equipped with a safe area guide and a Next.js Metadata code generation function. This is the ultimate OGP simulator, allowing you to confirm every detail with pixel-perfect accuracy before publishing.

A command center tool for font size design that supports building design systems in the responsive era. It provides all the necessary functions for font size design, including PX⇔REM conversion, Visual Ruler, Tailwind Suggestion, Modular Scale, and Fluid Typography (clamp function) generation.

Generate TypeScript types, Zod schemas, and mock data all at once, just by pasting JSON. Includes a Smart Inference feature that intelligently infers by analyzing values and key names (with automatic detection of dates, emails, and URLs). Supports real-time conversion and JSON formatter.

Generates physics-based layered shadows, Glassmorphism, and Neumorphism. Includes Stripe, Vercel, and macOS-style presets, dynamic backgrounds, and a comparison feature. Outputs in CSS/Tailwind JIT/Tailwind Config format.

A background design tool that allows you to create aurora (mesh gradient) and noise textures, essential for modern web design, with intuitive GUI operations. It supports drag operations utilizing Framer Motion, Linear/Radial Gradient, non-linear easing functions, and SVG Noise Overlay. Includes CSS code generation and PNG export features.

Intuitively generate sophisticated, deep web backgrounds, as adopted by Vercel, Linear, and other companies. Includes 6 types of patterns such as Grid, Dots, and Graph Paper, along with Smart Masking (Vignette/Fade), Texture & Noise, and an Interactive Spotlight feature. Outputs in CSS/Tailwind/React Component formats.

A compensation calculation tool fully compatible with Japanese freelance practices. It supports both General modes (hourly rate/fixed fee) and SES modes (adjustment range). Features include Invoice System compliance, withholding tax calculation, crowdsourcing fee calculation (percentage/fixed amount), automatic business day calculation, and an annual income conversion function. Output is available in Email, Excel, and Notion formats.

Instantly check character count before SNS posts. Accurately calculates full-width and half-width characters, and provides real-time support for character limits on X, Instagram, TikTok, note, and LINE. Includes copy and clear functions.

BPMを入力するだけで全音符のディレイタイム（ms）・サンプル数・小節長を一覧表示。FL Studio / MPC / SP-404 のディレイ設定やサンプルチョップに即使える。

JWTトークンをペーストするとHeader/Payload/Signatureをデコード。有効期限・発行日をリアルタイム判定。すべてブラウザ内処理でトークンが外部送信されない。

正規表現をリアルタイムテスト。マッチ箇所を色分けハイライト、キャプチャグループを一覧表示。メール・URL・日付・日本語電話番号などのプリセット付き。

cron式を入力すると次回10件の実行日時をJSTとUTCで並列表示。逆引き機能でよく使うスケジュールからcron式を生成。GCP Cloud Scheduler / Vercel Cron / GitHub Actions対応。

HEX / RGB / HSL を相互変換。2色のWCAGコントラスト比をAA/AAA基準で判定。Tailwindパレットへの近似色マッピング付き。CSSカスタムプロパティをワンクリックコピー。

ブラウザ完結の16ステップドラムシーケンサー。パターンを組んで▶再生、.midファイルでFL Studio / MPC / Abletonに書き出し。自分のサンプルをドロップして使うことも可能。

WAV/MP3をドロップするだけで無音トリム・ノーマライズ・フェードイン/アウトを一括処理。SP-404 / MPC / FL Studio に読み込む前の下処理をブラウザで完結。外部送信なし。