> For the complete documentation index, see [llms.txt](/llms.txt). [miniwebtool /api](/) [tools](/tools/) [docs](/docs/) [reference](/v1/docs) [pricing](/#pricing) [log in](/dashboard/login/) [get free key →](/billing/checkout/?plan=free) 001 hosted utility endpoints · since 2010 # Every boring endpoint, already built. Calculators, converters, hashes, date math, and finance formulas as stable JSON APIs. One bearer token, one credit pool, schemas that don't drift. You ship the feature; we maintain the formula. ✓ OpenAPI 3.1 ✓ RFC 7807 errors ✓ MCP built in ✓ failed calls cost 0 [Get a free key →](/billing/checkout/?plan=free) [View reference](/v1/docs) ✓ the same engines behind [miniwebtool.com](https://miniwebtool.com) — tools people have searched for and used since 2010 curl python node LIVE ```text $ curl https://api.miniwebtool.com/v1/tools/percentage-calculator/run \ -H "Authorization: Bearer $MWT_KEY" \ -d '{"mode":"percent_of","a":15,"b":200}' { "request_id": "01KPW8…", "tool": "percentage-calculator", "credits_used": 1, "result": { "mode": "percent_of", "a": 15, "b": 200, "result": 30 } } ``` ```text import requests, os r = requests.post( "https://api.miniwebtool.com/v1/tools/percentage-calculator/run", headers={"Authorization": f"Bearer {os.environ['MWT_KEY']}"}, json={"mode": "percent_of", "a": 15, "b": 200}, timeout=10, ) print(r.json()["result"]["result"]) # 30 ``` ```text const res = await fetch( "https://api.miniwebtool.com/v1/tools/percentage-calculator/run", { method: "POST", headers: { "Authorization": `Bearer ${process.env.MWT_KEY}`, "Content-Type": "application/json", }, body: JSON.stringify({ mode: "percent_of", a: 15, b: 200 }), }, ); const { result } = await res.json(); console.log(result.result); // 30 ``` 200 OK · 1 credit · application/json Start free · no card Paid plans from $29/mo for production volume POST /car-depreciation-calculator 2cr POST /car-lease-calculator 2cr POST /bond-equivalent-yield-calculator 2cr POST /bond-yield-to-maturity-calculator 2cr POST /zero-coupon-bond-calculator 2cr POST /character-counter 1cr POST /compare-two-strings 1cr POST /find-longest-line 1cr POST /line-counter 1cr POST /pangram-checker 1cr POST /blake2b-hash-generator 1cr POST /md5-hash-generator 1cr POST /sha256-hash-generator 1cr POST /sha3-512-hash-generator 1cr POST /sha384-hash-generator 1cr POST /complementary-error-function-calculator 1cr POST /exponential-decay-calculator 1cr POST /exponential-growth-calculator 1cr POST /antilog-calculator 1cr POST /absolute-value-equation-solver 1cr POST /random-playing-card-generator 1cr POST /random-color-generator 1cr POST /random-date-generator 1cr POST /list-randomizer 1cr POST /random-group-generator 1cr POST /cpc-calculator 1cr POST /cpm-calculator 1cr POST /value-of-a-visitor-calculator 2cr POST /css-box-shadow-generator 1cr POST /css-compressor 1cr POST /color-contrast-checker 1cr POST /color-code-converter-all-formats 1cr POST /color-scheme-generator 1cr POST /board-foot-calculator 1cr POST /carpet-calculator 1cr POST /decking-calculator 1cr POST /tile-calculator 1cr POST /wallpaper-calculator 1cr POST /fuel-efficiency-converter-mpg-l-100km-km-l 1cr POST /torque-converter-nm-ft-lb-kgf-cm 1cr POST /baking-pan-size-converter 1cr POST /dough-hydration-calculator 1cr POST /coffee-brew-ratio-calculator 1cr POST /cooking-unit-converter 1cr POST /cups-to-grams-converter 1cr POST /cross-stitch-size-calculator 1cr POST /youtube-earnings-estimator 1cr POST /autumnal-equinox-day 1cr POST /decimal-to-time-converter 1cr POST /cmyk-to-hex-converter 1cr POST /hex-to-cmyk-converter 1cr POST /hex-to-rgb-converter 1cr POST /rgb-to-hex-converter 1cr POST /base64-decoder 1cr POST /xml-to-json-converter 1cr POST /yaml-formatter-validator 1cr POST /xml-validator 1cr POST /text-to-binary-hex-ascii-converter 1cr POST /unix-permission-calculator 1cr POST /transformer-calculator 1cr POST /voltage-divider-calculator 1cr POST /battery-life-calculator 1cr POST /voltage-drop-calculator 1cr POST /wire-gauge-calculator 1cr POST /water-usage-calculator 1cr POST /wedding-alcohol-calculator 1cr POST /beading-pattern-calculator 1cr POST /yarn-calculator 1cr POST /bench-press-calculator 1cr POST /bmr-calculator 1cr POST /bac-calculator 1cr POST /ctr-calculator 1cr POST /tire-size-calculator 1cr POST /test-score-calculator 1cr POST /weighted-grade-calculator 1cr POST /daily-time-savings-calculator 1cr POST /boiling-point-calculator 1cr POST /astronomical-unit-converter 1cr POST /percent-yield-calculator 1cr POST /parallel-resistor-calculator 1cr POST /power-factor-calculator 1cr POST /rc-time-constant-calculator 1cr POST /at-bats-per-home-run-calculator 1cr POST /batting-average-calculator 1cr POST /era-calculator 1cr POST /fip-calculator 1cr POST /ops-calculator 1cr POST /halfway-date-calculator 1cr POST /when-is-leap-year 1cr POST /date-calculator 1cr POST /date-difference-calculator 1cr POST /time-between-two-dates 1cr POST /winter-solstice-day 1cr POST /car-depreciation-calculator 2cr POST /car-lease-calculator 2cr POST /bond-equivalent-yield-calculator 2cr POST /bond-yield-to-maturity-calculator 2cr POST /zero-coupon-bond-calculator 2cr POST /character-counter 1cr POST /compare-two-strings 1cr POST /find-longest-line 1cr POST /line-counter 1cr POST /pangram-checker 1cr POST /blake2b-hash-generator 1cr POST /md5-hash-generator 1cr POST /sha256-hash-generator 1cr POST /sha3-512-hash-generator 1cr POST /sha384-hash-generator 1cr POST /complementary-error-function-calculator 1cr POST /exponential-decay-calculator 1cr POST /exponential-growth-calculator 1cr POST /antilog-calculator 1cr POST /absolute-value-equation-solver 1cr POST /random-playing-card-generator 1cr POST /random-color-generator 1cr POST /random-date-generator 1cr POST /list-randomizer 1cr POST /random-group-generator 1cr POST /cpc-calculator 1cr POST /cpm-calculator 1cr POST /value-of-a-visitor-calculator 2cr POST /css-box-shadow-generator 1cr POST /css-compressor 1cr POST /color-contrast-checker 1cr POST /color-code-converter-all-formats 1cr POST /color-scheme-generator 1cr POST /board-foot-calculator 1cr POST /carpet-calculator 1cr POST /decking-calculator 1cr POST /tile-calculator 1cr POST /wallpaper-calculator 1cr POST /fuel-efficiency-converter-mpg-l-100km-km-l 1cr POST /torque-converter-nm-ft-lb-kgf-cm 1cr POST /baking-pan-size-converter 1cr POST /dough-hydration-calculator 1cr POST /coffee-brew-ratio-calculator 1cr POST /cooking-unit-converter 1cr POST /cups-to-grams-converter 1cr POST /cross-stitch-size-calculator 1cr POST /youtube-earnings-estimator 1cr POST /autumnal-equinox-day 1cr POST /decimal-to-time-converter 1cr POST /cmyk-to-hex-converter 1cr POST /hex-to-cmyk-converter 1cr POST /hex-to-rgb-converter 1cr POST /rgb-to-hex-converter 1cr POST /base64-decoder 1cr POST /xml-to-json-converter 1cr POST /yaml-formatter-validator 1cr POST /xml-validator 1cr POST /text-to-binary-hex-ascii-converter 1cr POST /unix-permission-calculator 1cr POST /transformer-calculator 1cr POST /voltage-divider-calculator 1cr POST /battery-life-calculator 1cr POST /voltage-drop-calculator 1cr POST /wire-gauge-calculator 1cr POST /water-usage-calculator 1cr POST /wedding-alcohol-calculator 1cr POST /beading-pattern-calculator 1cr POST /yarn-calculator 1cr POST /bench-press-calculator 1cr POST /bmr-calculator 1cr POST /bac-calculator 1cr POST /ctr-calculator 1cr POST /tire-size-calculator 1cr POST /test-score-calculator 1cr POST /weighted-grade-calculator 1cr POST /daily-time-savings-calculator 1cr POST /boiling-point-calculator 1cr POST /astronomical-unit-converter 1cr POST /percent-yield-calculator 1cr POST /parallel-resistor-calculator 1cr POST /power-factor-calculator 1cr POST /rc-time-constant-calculator 1cr POST /at-bats-per-home-run-calculator 1cr POST /batting-average-calculator 1cr POST /era-calculator 1cr POST /fip-calculator 1cr POST /ops-calculator 1cr POST /halfway-date-calculator 1cr POST /when-is-leap-year 1cr POST /date-calculator 1cr POST /date-difference-calculator 1cr POST /time-between-two-dates 1cr POST /winter-solstice-day 1cr Endpoints 520 curated, growing catalog Auth 1 key same bearer token everywhere Cost per call fixed published credit weight per tool Failed calls 0 credits 4xx/5xx auto-refund 002 the contract ## One envelope. Stable errors. Honest headers. Everything you'd check before trusting a third-party API, in one glance. The same shape on every endpoint — integrate once, reuse for all 520 tools. response envelope ```text { "request_id": "01KPW8…", "tool": "", "tool_version": "1.0.0", "credits_used": 1, "result": { …typed output… } } ``` errors · RFC 7807 ```text { "status": 402, "code": "insufficient_credits", "title": "Insufficient credits", "request_id": "01KPW…" } // branch on `code` — it never changes ``` every response ```text X-RateLimit-Limit: 10 X-MWT-Credits-Used: 1 X-MWT-Credits-Remaining: 49998 X-Request-Id: 01KPW… ``` 003 who builds on this [ [saas] Product teams Calculators in dashboards, forms, and onboarding flows ](/tools/) [ [fin] Financial sites Interest, mortgage, APY, ROI — audited formulas ](/tools/category/finance/) [ [edu] Education apps Practice, quizzes, step-by-step explanations ](/tools/) [ [mcp] Agents & automation Exact tool calls over MCP after the LLM plans ](/docs/#mcp) 004 why pay for "simple" ## The formula is the easy part. Anyone can write`a / b * 100`. What eats your sprint is everything around it: input validation, edge cases, rounding rules, examples, docs that stay current, rate limits, and a billing story. We package that operational work behind one HTTP call — and we've been maintaining these exact tools in production since 2010. Ship the feature this afternoon POST a JSON body, render`result`. No formula review, no test matrix for edge cases you haven't thought of yet. Integrate once, reuse 520 times Same auth, same envelope, same error codes on every endpoint. Your client wrapper is ~20 lines, total. Predictable bill, no surprises Each tool's credit weight is published in the OpenAPI spec. Failed calls refund automatically. Hard caps by default. ## Best-fit use cases - Calculator features inside dashboards, forms, or onboarding flows. - Finance, education, and content sites that need utility endpoints that just work. - Agencies and automation builders running many small tools under one account. - AI agents that plan in natural language but need exact, deterministic execution. [Browse all endpoints →](/tools/) [Read docs](/docs/) 005 pricing ## Free to evaluate. Cheap to ship. Start free, no card. Upgrade when an endpoint becomes part of your product. Cancel anytime from the Stripe portal — no sales call required. Monthly Yearly −16% ### Free Free 1,000 credits/mo 1 req/sec Hard cap Testing and prototypes Core text, hash, math, date, and conversion tools [Start free](/billing/checkout/?plan=free) ### Starter $ 29 /mo 75,000 credits/mo 5 req/sec Hard cap + manual packs Indie apps and automations Core plus basic finance [Start Starter](/billing/checkout/?plan=starter&cycle=monthly) POPULAR ### Pro $ 79 /mo 400,000 credits/mo 15 req/sec Hard cap default; optional $0.25 / 1K credits Production SaaS and content workflows Core, finance, text, random, and webmaster light [Start Pro](/billing/checkout/?plan=pro&cycle=monthly) ### Business $ 199 /mo 1,500,000 credits/mo 50 req/sec Hard cap default; optional $0.15 / 1K credits Teams and production apps All sync APIs, logs, invoices, team controls [Start Business](/billing/checkout/?plan=business&cycle=monthly) ### Scale $ 499 /mo 5,000,000 credits/mo 100 req/sec Hard cap default; optional $0.10 / 1K credits High throughput and batch usage Higher limits, priority queue, crawler add-ons later [Start Scale](/billing/checkout/?plan=scale&cycle=monthly) Yearly billing: pay 10 months, get 12. Need >5M/mo, SOC 2, or a DPA? [sales@miniwebtool.com](mailto:sales@miniwebtool.com) ## First`curl`in 30 seconds. Verify your email → get a key → stable JSON. No card, no SDK, no tool build-out. [Get a free key →](/billing/checkout/?plan=free) API OPERATIONAL v1 · OpenAPI 3.1 · MCP 2025-06-18 [terms](https://miniwebtool.com/about/terms-and-disclaimer/#api-terms) [privacy](https://miniwebtool.com/about/privacy/#api-privacy) [llms.txt](/llms.txt) [consumer site →](https://miniwebtool.com) © 2026 miniwebtool