ToolkitBook
ToolkitBook is a free collection of browser-based tools for developers, students, creators, and everyday tasks. Format and minify CSS, JavaScript, HTML, JSON, and XML; convert images, SVGs, units, color spaces, JSON, XML, and HTML; calculate mortgages, interest, BMI, areas, volumes, projector sizes, and number bases. Generate passwords, JWT keys, pixel avatars, and printable math worksheets. Analyze words, characters, keyword frequency, Chinese text, and sitemap files. Tools run locally in your browser, so your files and text do not need to be uploaded.
Format, beautify, optimize, or minify CSS stylesheets with live size stats and browser-side processing.
Drag and drop CSS files to format, optimize, or minify them in a single browser batch. Choose a mode and download each result with its original filename.
Messy or minified JavaScript? Format code, remove comments, strip console.log, or minify scripts with browser-side Terser.
Upload multiple .js files to format, optimize, strip console/debugger code, or minify JavaScript in your browser. Download each processed file.
Paste JSON to format, validate, sort keys, or minify output. Processing runs in your browser; nothing is uploaded to a server.
Convert JSON to XML online. Paste JSON or drag in a .json file to get indented XML with escaped characters. Runs in your browser; no upload.
Paste XML or drag in a .xml file to convert it to formatted JSON. The browser-based tool validates XML syntax before conversion.
Calculate and compare simple vs. compound interest. Enter principal, choose annual, monthly, or daily rates, set a term, and see interest earned and final balance.
Enter home price, down payment, and rate to see your full PITI breakdown with taxes, insurance, and PMI. Runs in your browser — no data uploaded.
Count words, characters, sentences, paragraphs, and reading time for pasted text, with characters without spaces and word frequency results.
Paste Chinese text to count characters, check HSK level distribution, and view frequency rankings with pinyin for each unique character.
Paste text, search for specific words, and get counts, percentages, and highlighted matches. Free, browser-based — your text stays on your device.
Calculate projector throw distance or maximum screen size for a room. Enter a throw ratio and get results in meters, feet, centimeters, and inches.
Start a free online stopwatch for workouts, talks, cooking, study, and games. Run multiple timers, record laps and splits, and copy HH:MM:SS.cc results.
Calculate the area of 10 2D shapes — circles, triangles, rectangles, and more. Enter any consistent unit to see the formula and related measurements.
Calculate volume for 11 3D shapes with formulas and extra measurements. Enter consistent dimensions; results use the matching cubic unit.
Create single-digit to 5-digit addition worksheets for classroom or home practice. Choose problem counts, use no-carry mode, and print answer keys separately.
Create printable subtraction worksheets with 1-5 digit numbers, optional no-borrowing mode, and separate answer keys. Free browser-based tool.
Create multiplication worksheets with 1–5 digits per factor, 10–100 unique problems, and separate printable answer keys. Free, no sign-up.
Need division worksheets with no remainders? Generate 10–100 custom problems with 1–5 digit numbers. Print separate answer keys. Free, no sign-up.
Paste sitemap.xml content to find XML syntax errors, protocol issues, and duplicate URLs. Review severity-labeled reports without uploading a file.
Generate secure random passwords with custom length and character types. Create up to 20 at once with no sign-up or server transmission. Free browser-based tool.
Convert metric and imperial length, weight, volume, temperature, area, and speed. Choose units and see the formula for each result.
Enter height and weight to get your BMI score, weight category, and healthy range. Supports metric and imperial units. Calculations run in your browser.
Add text watermarks to ID card copies before sharing. Customize text, opacity, rotation, and tiled patterns in your browser, then download the watermarked file.
Sharing passport copies for visas or ID checks? Add tiled text watermarks in your browser with no server upload or sign-up. Download as PNG, JPEG, or WebP.
Generate HS256, HS384, or HS512 JWT secret keys in Hex, Base64, or Base64URL with special-character mode. Processing runs locally in your browser.
Check keyword density for SEO. Paste text to count word frequency, view each term's percentage share, filter stop words, and export CSV results.
Upload a TXT or searchable PDF to count word frequency, filter stop words or target terms, and export a CSV from your browser.
Free image converter for PNG, JPEG, WebP, and BMP. Upload once, choose multiple output formats, and convert in your browser with no server upload.
Paste sitemap XML to get line-by-line error reports with code snippets. Click any issue to jump to its line. Runs in your browser; no file upload is required.
Upload a sitemap.xml file to check XML syntax, protocol issues, duplicate URLs, and SEO warnings with line numbers. Runs in your browser.
Convert between binary, octal, decimal, and hex in real time. Free online base converter — all four number systems shown at once, browser-based.
Convert RGB values to CMYK percentages and back with a color picker, live preview, HEX, and HSL readouts for print preparation.
Convert Gregorian dates to Chinese lunar dates and back. View Gan-Zhi years, zodiac animals, and leap month details for 1900–2100.
Turn a photo into 8-bit pixel art with adjustable scale and output size. Create avatars, game assets, or retro artwork, then download a PNG.
Calculate Beamer slide and text area dimensions, adjust margins, and generate LaTeX code with results in mm, pt, and inches.
Flip a cryptographically random coin, add custom heads and tails labels, and track results with statistics and a 20-flip history in your browser.
Need cylinder volume from diameter or radius? Enter dimensions in mm, cm, m, in, or ft to get volume, surface area, and a step-by-step breakdown.
Paste HTML to format it with proper indentation, remove HTML/CSS/JS/Jinja2 comments, strip empty lines, and check syntax. All processing runs in your browser.
Upload .html or .htm files, format indentation, remove comments or blank lines, check syntax, and download processed files as a ZIP in your browser.
Paste any HTML and get clean Markdown. Links, tables, and code blocks preserved. Runs in your browser — no data uploaded. Free with no signup required.
Browse 151 traditional Japanese color swatches with hex codes, romaji, kanji, and English names. Filter by 11 families, search names or hex, and copy hex codes.
Browse 150+ traditional Chinese color swatches with hex values, pinyin, and cultural context. Search, filter, and copy hex codes.
Messy or minified XML? Paste your code to format, beautify, or compress it — built-in validation with line-numbered error reports. Free, no sign-up.
Format or minify multiple XML files at once — drag, drop, and process your entire batch locally in your browser. Free, no sign-up required.
Paste SVG code to convert it to PNG, JPEG, or WebP with live preview, custom dimensions up to 8192 x 8192, and browser-based rendering.
Encode or decode Base64 online with URL-safe mode, configurable padding, UTF-8 text support, and one-click copy in a browser-based tool.
Paste an encoded string to detect its format and decode it. Supports Base64, Base64URL, URL, Hex, HTML entities, Base32, and ROT13. Runs in your browser.
Sort objects inside JSON arrays by one or more keys. Apply chained ascending or descending rules to nested arrays; processing runs in your browser.