Your all-in-one free online toolbox

Count tokens with real OpenAI tokenizers (cl100k_base / o200k_base).

Estimate any LLM API cost from token counts and your own per-1M-token prices.

Convert a plain chat transcript into OpenAI messages JSON.

Generate JSON Schema draft-07 from a JSON sample for function calling.

Send a test request to any LLM API and get curl, Python, Node, Go and PowerShell code.

Format, validate and minify JSON in your browser. No data is ever uploaded.

Compare two JSON documents side by side and see differences instantly.

Decode JWT tokens, inspect the header and payload, and verify signatures.

Encode text or files to Base64, or decode Base64 back to readable text.

Generate SHA-1/256/384/512 and MD5 hashes using your browser Web Crypto.

Generate cryptographically secure random UUID v4 / GUID values in bulk.

Convert Chinese characters to pinyin with automatic polyphonic disambiguation.

Parse cron expressions into a human-readable schedule with next run times.

Count characters, words, lines and CJK characters in real time.

Convert text between camelCase, snake_case, Title Case and more.

Test JavaScript regular expressions with live match highlighting.

Convert numbers between base 2 and 36 with BigInt precision.

Generate strong, secure passwords with a strength meter.

Convert length, weight, temperature, area, volume, speed and data.

Compare two texts or code snippets and highlight the differences line by line.

Write Markdown with live preview, toolbar shortcuts, and export.

Create diagrams from text with live Mermaid rendering and export.

Look up command-line cheat sheets from cheat.sh for any tool.

Encode or decode URLs and URL components with configurable options.

Compute network, broadcast, mask and host ranges from any CIDR block.

Look up the meaning of any HTTP status code, grouped by class.

Find the service behind well-known TCP and UDP ports.

Validate IPv4/IPv6 addresses and convert between decimal, binary and hex.

Query A, AAAA, MX, TXT and more records over DNS-over-HTTPS.

Generate random MACs, reformat addresses and look up the vendor (OUI).

Compose curl commands visually with method, headers and body.

Convert bit/s, KB/s, MB/s and GB/s, with download-time estimates.

Browse all standard DNS record types with numbers and meanings.

Merge overlapping CIDRs and compute the smallest supernet.

Generate random IPv4, IPv6 addresses and CIDR blocks in bulk.

Test DingTalk custom robot messages with text, markdown, link and actionCard.

Test WeCom group robot messages with text, markdown, markdown_v2 and news.

Convert between Unix timestamps and human-readable dates, in seconds or milliseconds.

Format any date with common presets or your own YYYY-MM-DD template.

Convert a time between any two time zones and see multiple world clocks at once.

Calculate the exact difference between two dates in years, months and days.

Turn a date into friendly relative time like "3 hours ago" or "in 2 days".

Count down to a target time, run a stopwatch with laps, or focus with a Pomodoro timer.

Compress and convert JPG, PNG and WebP images in your browser with a quality slider.

Convert colors between HEX, RGB, HSL, HSV, CMYK and generate palettes.

Extract text from screenshots and photos with tesseract.js OCR.

Generate QR codes with custom colors, size and error correction level.

Scan QR codes with your webcam or from an uploaded image.

Generate CODE128, EAN, UPC and other barcodes with JsBarcode.

Combine multiple PDF files into one, reorder pages, all in your browser.

Split a PDF by page range, every N pages, or extract selected pages.

Turn Markdown into a styled, downloadable PDF — fully in your browser.

Extract all text from a PDF with one click, then copy or download it as TXT.

Convert PDF pages to PNG images with a chosen scale, page range and watermark.

Stamp text watermarks across every page with opacity, rotation and tiling.

Add page numbers to any PDF with a custom format, position and start number.

Reduce PDF file size by re-rendering pages at your chosen resolution and quality.

Combine JPG, PNG and WebP images into a single PDF in your browser.

Reorder, delete and rotate PDF pages with visual thumbnails.

Convert numbers to Chinese financial capital letters (壹贰叁…) for invoices.

China salary income tax with cumulative monthly withholding table.

Compare separate vs. combined taxation of the year-end bonus.

Compute employee and employer shares of China social insurance.

Convert gross salary to take-home pay after social insurance and tax.

Compute stamp duty for common contracts under the 2022 law.

Calculate the 0.05%-per-day late-payment penalty on overdue tax.

Convert between tax-inclusive and tax-exclusive prices at any rate.

Convert currencies with daily official reference rates from the ECB.

Equal-installment and equal-principal amortization with a full schedule.

Project investment growth with compound interest and contributions.

Calculate fixed-deposit interest and maturity value with rate presets.

Find your Chinese zodiac animal by birth year.

Find your Western zodiac sign by birth date.

Calculate your Body Mass Index and see the health category.

Estimate your baby's due date from last menstrual period.

Calculate your statutory retirement age and date (China policy).

Check real-time weather and 3-day forecasts for any city via wttr.in.