All Tools
Every tool we make. Free, browser-based, no account required.
The catalog keeps growing. Developer utilities for formatting, validating, and converting. Design tools for color, type, gradients, and favicons. Home and DIY calculators for paint, drywall, flooring, framing, and garden beds. Everyday essentials covering finance, privacy, statistics, and health. New tools ship every few weeks — search what's here, or jump to a category to see what's already in your corner.
The compound interest calculator that doesn't get in your way.
Drag sliders, watch your money grow. Real-time compound interest with a stacked growth chart and a full year-by-year breakdown.
Try it 02See what your photos are hiding, then strip it.
In-browser metadata removal for JPEG, PNG, WebP, and HEIC. Preview GPS, device IDs, and timestamps before wiping them in one click.
Try it 03COGS, gross profit, and margin in one calculation.
Enter inventory and costs, get COGS, gross profit, gross margin, and a step-by-step formula breakdown instantly.
Try it 04Paste. Compare. Copy the diff.
Semantic diff for JSON & YAML with color-coded comparison and copyable plain-text summaries.
Try it 05Accurate drywall sheets in seconds.
Drywall sheet estimator with door/window deductions, accessories breakdown, and cost estimate in under 60 seconds.
Try it 06The Unix timestamp converter that tells you what you're looking at.
Auto-detects seconds, milliseconds, microseconds, or nanoseconds. Multi-format output with one-click copy.
Try it 07Your favicon set, dark-mode ready, in 90 seconds.
Favicon package generator producing dark-mode-ready SVG favicons and cross-platform icon sets, fully processed in the browser.
Try it 08CSS gradients with Tailwind output and OKLCH color quality.
Visual gradient builder with perceptual color space interpolation, Tailwind-native code output, and one-click copy.
Try it 09Drop an image, paste a :root.
Image-to-palette extractor with CSS custom properties, Tailwind v3/v4 output, JSON design tokens, and a WCAG contrast pairings matrix.
Try it 10Convert colors instantly. Copy in one click.
HEX, RGB, HSL, and CMYK conversion in real time with a session color history that persists across page refreshes.
Try it 11The jq playground developers actually keep open.
WASM-powered jq execution with shareable permalinks, curated examples, and persistent query history.
Try it 12The fastest, cleanest JSON formatter online.
Instant beautify and minify with syntax highlighting, error positions, and one-click copy.
Try it 13Compress images in your browser. No uploads. No limits. No account.
Browser-only batch image compressor with a live before/after slider, unlimited queue, and zero network requests.
Try it 14Know exactly how many boxes to buy.
Flooring calculator for hardwood, laminate, LVP, tile, and carpet with smart waste defaults per material type and cost estimates.
Try it 15See exactly which cron field is wrong, and why.
Field-level cron validation with human-readable schedule descriptions and next execution dates.
Try it 16Density, mass, volume — solved and explained.
Three-variable calculator with unit conversion across 24 units, step-by-step breakdowns, and a material reference table.
Try it 17Know exactly how much mulch you need. Instantly.
Cubic yard and bag count estimates for garden beds. Enter dimensions, pick depth, get your shopping list.
Try it 18Hex math that shows its work in every base.
Hex calculator with arithmetic and bitwise operations, plus live output in hex, decimal, octal, and binary.
Try it 19Every down payment scenario, side by side.
Compare 3%, 5%, 10%, and 20% down payments with real PMI costs, monthly payments, and total cash needed at closing.
Try it 20Paste a messy table. Get a perfect one. Instantly.
Markdown table formatter with live preview and correct CJK wide-character alignment.
Try it 21Test statistic in, p-value out. 30 seconds.
P-value calculator for Z, T, chi-square, and F distributions with tail selection and plain-English significance interpretation.
Try it 22Contrast ratio, instantly clear.
WCAG 2.2 + APCA contrast checker that shows the closest on-brand fix for failing color pairs and generates shareable permalinks.
Try it 23Build an RBAC matrix. Export it anywhere.
Checkbox-grid permission matrix generator with export to CSV, Markdown, and JSON. No spreadsheet required.
Try it 24The wallpaper roll calculator that prints your shopping list.
Per-wall wallpaper roll calculator with door and window deductions, pattern match handling, a waste slider, and a printable shopping list.
Try it 25CSV to JSON in one paste.
Auto-delimiter detection, four JSON output modes, pretty-print or compact, download or copy.
Try it 26Hit space. Get colors that actually pass.
Spacebar-fast, accessibility-first color palette builder. WCAG 2.1 AA/AAA and APCA scored on every pair, with plain-language coaching and CSS / Tailwind v4 export.
Try it 27Am I intoxicated? How long until I'm sober?
BAC calculator with custom ABV per drink, color-coded results against the legal limit, and an estimated time-to-sober countdown.
Try it 28Mark your studs right the first time.
Stud spacing calculator with a printable layout template showing exact stud positions. The output no competitor offers.
Try it 29Format SQL in seconds. No login. No install.
14 SQL dialects, keyword case controls, indentation options, and a unique before/after diff view.
Try it 30Token count, cost, and context window for GPT, Claude, and Gemini.
Multi-model token counter with cost estimation, context window usage, and live stats. Everything runs in your browser.
Try it 31Font pairings that explain themselves.
Curated heading/subheading/body trios from Google Fonts with plain-language explanations of why each pairing works.
Try it 32Know exactly what to buy before you hit the paint aisle.
Accent wall paint calculator with door/window subtraction, cost estimates at three price tiers, and a printable shopping list.
Try itHow these tools are built
Every tool on AppCrib is a static site that ships to your browser once and runs there. No servers hold your data, because the tools don't need servers. Paste JSON into jsonr, strip EXIF from a photo in Blank, measure a wall in Drywl — all of it runs in your tab. Nothing leaves. That's not a marketing pose. It's the only technical model that can credibly promise your data stays yours.
It also makes everything fast. No spinners, no queue, no cold-start latency dragging a 400ms round trip onto a one-second calculation. Input changes, output updates, done.
The standard they share
Every tool uses the same design system. Same type scale, same color logic, same dark mode, same spacing grid. Someone who's used jqbin already knows how to use Rolemat without reading a tutorial. That's the point of shipping many small tools instead of a handful of large ones — consistency is a feature, and building it once means every new tool inherits it.
Same privacy model across the catalog. Same performance bar. Same refusal to block the interface with modals or sign-up walls.
Browse by category
Each category has its own landing page where the tools are grouped with a bit more context on what they're for. The lineup in each one keeps expanding.
- Developer Tools11 tools
Formatters, validators, converters, and playgrounds. Every one runs in your browser, respects your data, and doesn't look like it was built in 2008.
- Design Tools6 tools
Color, contrast, type, gradients, and favicons. The small tools designers and front-end developers reach for every week, finally done well.
- Home & DIY Tools6 tools
Paint, drywall, flooring, studs, mulch. The calculators that tell you exactly what to buy before you drive to the store.
- Everyday Tools8 tools
Finance calculators, privacy tools, statistics utilities, and health checks. Everyday tools that don't need a login or a subscription.
New tools ship regularly
The catalog grows every few weeks — we spot a gap in the free-tool landscape and ship something that fills it. Launch notes and technical deep-dives live on the blog, which is the best way to follow along without checking back here.