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在线即时格式化、验证和美化 JSON 数据。100% 客户端隐私保护。

即时编码或解码 Base64。没有数据发送到服务器。

Convert images to Base64 strings and preview Base64 image data directly in your browser.

安全地编码或解码 URL 字符串。特殊字符将正确转换。

Decode JWT headers and claims locally for inspection.

Generate test JWTs for development workflows.

Calculate investment growth with deposits, monthly contributions, interest rates, and a visual year-by-year chart.

Calculate percent of a value, percentage ratio, and percent change instantly.

Calculate percent increase or decrease between two values instantly.

Calculate discount amount, sale price, tax, and final price.

Calculate true per-order profit after product cost, shipping, packaging, ads, fees, and expected returns.

Estimate seller fees, payment fees, listing costs, shipping impact, and net payout for marketplace orders.

Find billable shipping weight from package dimensions, actual weight, and carrier divisor.

Find the ROAS, ACOS, and maximum ad spend that keeps an ecommerce order profitable.

Preview how a page title, URL, and meta description may appear in Google-style search results.

Check meta title and description length with practical SEO snippet guidance.

Preview Open Graph metadata and generate copy-ready OG tags for social sharing.

Preview Twitter/X card metadata and generate copy-ready card tags.

Design CSS box shadows visually and copy the generated CSS.

Create polished linear, radial, and conic CSS gradients with copy-ready output.

Convert colors between HEX, RGB, HSL, and CMYK.

Generate harmonious color palettes from a base color for UI, branding, and creative work.

Calculate body mass index from metric height and weight.

Calculate age in years, months, and days from dates.

Calculate the duration between two calendar dates.

Calculate GPA from grade points and course credits.