Paste text and instantly measure words, characters, sentences, paragraphs, and estimated reading time.
Reviewed public catalog
Focused browser tools with documented limits
ZZP Box publishes a deliberately small catalog of browser-local tools for text, structured data, URLs, crawl controls, and search metadata. Every public tool has a real workspace, a reproducible example, stated limits, and a release test record.
Public catalog
Tools with documented behavior
The workspace, expected result, unsupported cases, privacy boundary, and release checks are stated on every tool page.
Change text casing quickly for headlines, labels, notes, and drafts without uploading your content.
Clean up JSON, make it readable, minify it for transport, and catch syntax errors before you paste it elsewhere.
Generate random passwords in your browser with selectable length and character types.
Encode text to Base64 or decode Base64 back to readable text in your browser.
Create campaign-tagged URLs for GA4, email, social, and paid links while preserving existing query parameters.
Convert common length, weight, and temperature units with clear formulas and instant browser-side results.
Encode text for URL components or decode percent-encoded strings in your browser for links, query parameters, and debugging.
Enter a birth date to calculate exact age and see how long remains until the next birthday.
Calculate business days between two dates with weekends and optional custom holidays excluded.
Convert JSON and a documented basic YAML subset in either direction without uploading the text.
Parse, sort, and validate dotenv assignments while keeping the text in the browser.
Calculate SHA-256 and inspect a local file header without sending the file to a server.
Inspect dimensions, crop risk, and approximate safe margins for common social preview shapes.
Generate srcset and sizes markup from image candidates you already created.
Preview deterministic filename changes and download a mapping without uploading file contents.
Convert an unambiguous local date and time between named IANA zones, inspect daylight-saving offsets, UTC, and date rollover in your browser.
Decode JWT header and payload JSON in your browser. This tool only decodes tokens and does not verify signatures.
Test JavaScript RegExp patterns against text in your browser with match count, indexes, syntax errors, and input length limits.
Parse and explain common 5-field cron expressions with validation for ranges, lists, steps, and unsupported scheduler-specific syntax.
Preview a Google-style search result with title, URL, and meta description checks for length, clarity, and truncation risk.
Generate Open Graph and Twitter Card meta tags from manually entered fields without fetching live pages.
Generate a robots.txt draft from manual user-agent, allow, disallow, sitemap, and crawl-delay settings.
Generate a basic sitemap.xml file from URLs you paste manually. This tool does not crawl or submit your website.
Generate a conservative CSS clamp() formula for responsive font-size values from min and max viewport settings.
Check foreground and background color contrast ratios with WCAG AA and AAA reference results.
Compare two JSON values and list added, removed, changed, and unchanged paths after validating the JSON input.
Calculate profit, profit margin, and markup from cost and selling price for simple business math planning.
Calculate sale price and savings from an original price and percentage or fixed discount.
Parse a URL into protocol, hostname, port, path, query parameters, and hash locally in your browser.
Browse by task
Three focused categories
Developer & Data Tools
These eleven tools help inspect or transform structured data and development artifacts. Parser dialects, signature-verification boundaries and unsupported formats are stated on the relevant page.
View categorySEO & Web Tools
These nine tools support implementation and review, not ranking guarantees. Generated metadata, crawl files, responsive markup and filename mappings must still be tested in the destination site or platform.
View categoryEveryday & Business Tools
These ten tools cover recurring writing, scheduling, pricing and measurement tasks. Results state their assumptions and avoid pretending to replace legal, financial, security or accessibility review.
View categoryPractical guidance
Understand the result before using it
The guides explain where a browser tool stops and which checks still belong in the receiving application, search console, analytics platform, or deployment workflow.