Developer Utilities
Small developer utilities that save a trip to a random website. Encode and decode Base64, explain a regex, build UTM links, generate QR codes and vCards, and more — the everyday helpers. Free in your browser, and available by API when you need them in a script.
Developer Utilities
Calculate Net Promoter Score
NPS calculator with classifications
POST /biz/survey-nps-score-calculate$0.002Developer Utilities
Calculate Survey Response Rate from Sent and Completed Surveys
POST /biz/survey-response-rate-calc$0.002Developer Utilities
Calculate Concrete Volume Needed With Waste Allowance
POST /build/concrete-volume-calculate$0.002Developer Utilities
Estimate decking boards needed from area, width, and gap
POST /build/deck-board-count-estimate$0.002Developer Utilities
Calculate fence post count and even spacing
POST /build/fence-post-spacing-calc$0.002Developer Utilities
Calculate gravel volume for a driveway and estimate its weight
POST /build/gravel-volume-calculate$0.002Developer Utilities
Calculate combined insulation R-value from multiple layers
POST /build/home-insulation-r-value-combine$0.002Developer Utilities
Estimate HVAC BTU needed for room size
POST /build/hvac-btu-room-size-estimate$0.002Developer Utilities
Calculate wallpaper rolls needed with pattern-repeat waste
POST /build/wallpaper-roll-estimate$0.002Developer Utilities
Check CMYK rich black vs registration black
POST /color/cmyk-rich-black-check$0.002Developer Utilities
Color blind safe palette checker
test protanopia and deuteranopia
POST /color/color-blind-safe-palette-check$0.002Developer Utilities
Name a color scheme by mood
classify any hex color
POST /color/color-scheme-name-theme$0.002Developer Utilities
Estimate CMYK from a Pantone-style color name lookup
POST /color/pantone-cmyk-estimate$0.002Developer Utilities
Seeded random color generator
reproducible hex and color name
POST /color/random-color-name-seeded$0.002Developer Utilities
Scale a cocktail recipe to any batch size
POST /cook/cocktail-recipe-scale$0.002Developer Utilities
Estimate homebrew ABV from original and final gravity readings
POST /cook/home-brew-gravity-abv-estimate$0.002Developer Utilities
Suggest a Wine Pairing Category for a Dish
POST /cook/recipe-wine-pairing-category$0.002Developer Utilities
API cost per request estimator
plan usage and overages
POST /dev/api-cost-per-request-estimate$0.002Developer Utilities
Backup retention storage calculator with deduplication
POST /dev/backup-retention-storage-estimate$0.002Developer Utilities
Cloud instance effective hourly cost and reserved breakeven calculator
POST /dev/cloud-instance-cost-per-hour$0.002Developer Utilities
Log retention storage calculator
estimate capacity needed
POST /dev/log-retention-storage-estimate$0.002Developer Utilities
SLA uptime credit calculator
calculate service credit owed
POST /dev/server-uptime-sla-credit-calc$0.002Developer Utilities
Compost Carbon-to-Nitrogen Ratio Calculator
POST /eco/compost-ratio-carbon-nitrogen$0.002Developer Utilities
Estimate solar panels needed for your energy usage
POST /eco/solar-panel-count-estimate$0.002Developer Utilities
Build a Code 128 barcode payload and checksum
POST /enc/barcode-code128-payload$0.002Developer Utilities
Convert Morse code to a timed light signal pattern
POST /enc/morse-light-pattern$0.002Developer Utilities
Build a vCard QR payload string
vCard 3.0 generator
POST /enc/qr-vcard-payload$0.002Developer Utilities
Build a WiFi QR payload string for WPA, WEP, or open networks
POST /enc/qr-wifi-payload$0.002Developer Utilities
Phone installment payoff calculator
balance and months left
POST /fin/phone-upgrade-payoff-calc$0.002Developer Utilities
Compare streaming subscription total cost
monthly and annual
POST /fin/streaming-subscription-cost-compare$0.002Developer Utilities
Seeded bingo card generator
reproducible number cards
POST /game/bingo-card-seeded$0.002Developer Utilities
Board game playtime calculator
estimate total session length
POST /game/board-game-playtime-estimate$0.002Developer Utilities
Card game deck mana curve calculator
check your cost distribution
POST /game/card-game-deck-build-ratio$0.002Developer Utilities
D&D Encounter Difficulty Calculator and XP Budget
POST /game/dnd-encounter-difficulty-calc$0.002Developer Utilities
Video Game Backlog Completion Time Calculator
POST /game/game-backlog-completion-estimate$0.002Developer Utilities
Raffle ticket number generator
padded ranges and seeded shuffle
POST /game/raffle-ticket-numbers$0.002Developer Utilities
Seeded random team generator
shuffle people into even teams
POST /game/team-shuffle-seeded$0.002Developer Utilities
Trivia night round scoring calculator with wagers and leaderboard
POST /game/trivia-night-round-scoring$0.002Developer Utilities
Build a book club reading schedule with meeting checkpoints
POST /hobby/book-club-schedule-build$0.002Developer Utilities
Candle Burn Time Remaining and Wax Estimate Calculator
POST /hobby/candle-burn-time-estimate$0.002Developer Utilities
Compare appliance total cost of ownership over a fair lifespan
POST /home/appliance-lifetime-cost-compare$0.002Developer Utilities
Battery replacement annualized cost calculator
POST /home/battery-replacement-cost-per-year$0.002Developer Utilities
Garden bed plant spacing calculator
plan a grid layout
POST /home/garden-bed-layout-spacing$0.002Developer Utilities
Calculate grass seed coverage needed for a lawn
POST /home/lawn-seed-coverage-calc$0.002Developer Utilities
Calculate mulch volume needed for a garden bed in cubic feet and bags
POST /home/mulch-volume-calculate$0.002Developer Utilities
Calculate a seed-starting date from the last frost
POST /home/seed-starting-date-backcalculate$0.002Developer Utilities
Daily affirmation picker
deterministic choice by date
POST /life/affirmation-pick-seeded$0.002Developer Utilities
Seeded icebreaker question picker for work, parties, and family
POST /life/icebreaker-question-pick$0.002Developer Utilities
Password entropy calculator
estimate bits and crack time
POST /security/password-entropy-estimate$0.002Developer Utilities
Generate an Esports Double-Elimination Bracket
POST /sports/esports-bracket-seed-matchups$0.002Developer Utilities
Emoji shortcode lookup
convert :smile: to an emoji
POST /str/emoji-shortcode-lookup$0.002Developer Utilities
Lucas number calculator: L_n from L0=2, L1=1, free bigint
POST /math/lucas-number$0.002Developer Utilities
Palindrome number checker
same digits forward and back in any base
POST /numth/palindrome-number$0.002Developer Utilities
Cividis colormap sample
free
POST /color/cividis-sample$0.002Developer Utilities
ΔEITP (BT.2124) calculator
free
POST /color/delta-e-itp$0.002Developer Utilities
OKLab ΔE (ΔEOK) calculator
free
POST /color/delta-e-ok$0.002Developer Utilities
Paul Tol discrete palettes
free
POST /color/tol-palette$0.002Developer Utilities
Google Turbo colormap sample
free
POST /color/turbo-sample$0.002Developer Utilities
Yellowness index (ASTM)
free
POST /color/yellowness-index$0.002Developer Utilities
Remembrance Sunday date
free
POST /date/remembrance-sunday$0.002