FreeToolHub

Data Sources & Update Policy

Every dataset powering our calculators — its authoritative source, update frequency, and last verification date.

How we keep data accurate

FreeToolHub runs a self-enforcing data authority framework. Every calculation dataset is registered with its official source (IRS, SSA, state agencies, primary industry data). At every build, the site re-verifies that the shipped numbers still match independently hard-coded official values — a mismatch fails the build, so stale or wrong data can never reach production unnoticed.

  • Sourced: 54 datasets, 100 cited official sources — a dataset without a source cannot ship.
  • Cross-checked: official ground-truth values ↔ runtime data files ↔ offline fallback constants must agree (3-way consistency gate).
  • Formula-audited: calculation formulas are re-verified against official worked examples with citations (see the formula verification matrix in our public repository).
  • Fresh: scheduled updates with staleness detection — datasets past their review window raise alerts automatically.
  • Regression-proof: auto-updaters refuse to write older tax-year data over newer data.

This page reflects the data registry as of 2026-09-06. If you spot a discrepancy with an official source, please report it — we treat accuracy reports as highest priority.

DatasetUsed byUpdatesLast updatedEffectiveOfficial sources
1099-NEC/MISC Filing Rules/1099-nec-miscAnnual2026-01-012026 tax yearIRS — Form 1099-NEC InstructionsIRS — Form 1099-MISC Instructions
401(k) Contribution Limits/401k-vs-rothAnnual2025-11-132026 tax yearIRS Newsroom — 401(k) limit increases to $24,500 for 2026 (IR-2025-111)IRS Notice 2025-67 (2026 retirement-plan COLA, PDF)IRS — COLA Increases for Dollar Limitations (§415(c) 2026 = $72,000)
Advertising ROI & ROAS Formulas/roi-calculatorManual review2026-06-01Standard formulas — no expirationGoogle Ads — ROI & ROAS Guide
AI Background Removal Model (ONNX)/ai-bg-removerManual review2026-06-01Model v1.7.0 (ONNX WASM, downloaded on first use)@imgly/background-removal (npm)IMG.LY — Background Removal Docs
AI Image Upscaling Algorithm/ai-image-upscalerManual review2026-06-01Browser Canvas API — no expirationMDN — Canvas imageSmoothingQuality
AI Prompt Engineering Templates/prompt-generatorManual review2026-06-012026 template formatsOpenAI — Prompt Engineering Guide
AI Text Generation Models/ai-email-writer/ai-paraphraser/ai-resume-rewriterManual review2026-06-01Powered by GPT models (2026)OpenAI GPT API
Break-Even Analysis Formula & Assumptions/break-even-calculatorManual review2026-06-01Standard CVP (Cost-Volume-Profit) model — no expirationInvestopedia — Break-Even AnalysisSBA — Break-Even Analysis
Browser Image Processing APIs/image-resize/image-watermark/img-base64/webp-conv/svg-convertManual review2026-06-01Browser-native APIs — no expirationMDN — Canvas APIMDN — File API
Canvas API — Blur Filter/bg-blurManual review2026-06-01Browser Canvas API — no expirationMDN — CanvasRenderingContext2D.filter
Color Space Conversion Standards/color-pickerManual review2026-06-01W3C CSS Color Level 4 — no expirationW3C — CSS Color Module Level 4ICC — Color Management
Copyright & Public Domain Rules/copyright-pdAnnual2026-01-01U.S. Copyright Law (Title 17) — 2026U.S. Copyright Office — Duration of CopyrightCornell University — Copyright Term and the Public Domain
CSS Gradients Specification/css-gradientManual review2026-06-01W3C CSS Images Level 3 — no expirationMDN — CSS gradientW3C — CSS Images Module Level 3
Currency Exchange Rates/currencyDaily● live2026-09-06Live rates as of 2026-09-04Frankfurter API (ECB reference rates)
Date & Time Calculation Standards/date-diff/countdownAnnual2026-01-01Gregorian calendar — no expirationISO 8601 — Date and Time FormatIANA Time Zone Database
English Grammar Rules Database/grammar-checkerManual review2026-06-01Rule-based — no expirationCommon English Errors — rule base
EU VAT Rates — 27 Member States/vat-calculatorAnnual2026-01-012026 VAT rates (verified Jan 2026)EU Council — VAT RatesPwC — EU VAT Rate Table
Federal Income Tax Brackets/w2-vs-1099/capital-gains/self-employment-tax/crypto-profit/freelancer-tax/1099k-tax/401k-vs-rothAnnual2026-09-032026 tax yearIRS Rev. Proc. — Annual Inflation AdjustmentsIRS.gov — Tax Brackets & Rates
Freelance Industry Rate References/pricing-calculatorAnnual2026-01-012026 reference ratesUpwork — Freelancer Rate ReportGlassdoor — Salary Data
GDPR Regulation Text & Articles/gdpr-requestManual review2026-06-01GDPR (Regulation EU 2016/679) — effective since May 25, 2018EUR-Lex — GDPR Full Text
Guerrilla Mail Temporary Email API/temporary-emailReal-time● live2026-06-18Live API — real-timeGuerrilla Mail — Free Temporary Email API
HS Code Duty Rates (US, EU, UK)/tariff-calculatorAnnual2026-01-012026 tariff rates (approximate averages)US HTS — Harmonized Tariff ScheduleEU TARIC — Integrated TariffUK Trade Tariff
HSA / FSA Contribution Limits/hsa-fsa-calculatorAnnual2026-08-282026 tax yearIRS Pub 969 — Health Savings AccountsIRS Rev. Proc. 2025-19 — 2026 HSA/HDHP amounts
HTML Email Compatibility Standards/email-templateAnnual2026-01-012026 email client compatibilityCan I Email — Compatibility TableMailchimp — Email CSS Guide
Inflation Rate (CPI-U)/compoundMonthly2026-07-013.3% (BLS CPI-U trailing 12mo, 2026-07-01)BLS — Consumer Price Index
Invoice Generator Processing/invoice-generatorManual review2026-06-01N/A — 100% client-side, no external dataAll data stays in your browser — no server, no API, no cloud
IRS Life Expectancy Tables & RMD Rules/rmd-calculatorAnnual2026-08-172022 R2 Uniform Lifetime Table + Joint Life and Last Survivor Expectancy TableIRS — Pub 590-B: Distributions from Individual Retirement Arrangements
LLC Formation & Annual Fees by State/llc-costManual review2026-08-172026 fees (verified Aug 2026)State Secretary of State websitesLLC University — State-by-State LLC Costs
LLM API Pricing & Token Ratios/token-calculatorManual review2026-08-17Pricing as of August 2026 (subject to change)OpenAI PricingAnthropic PricingGoogle AI Studio PricingDeepSeek PricingMeta Llama — Together AI Pricing
LLM Tokenizer Character-to-Token Ratios/token-calculatorManual review2026-06-01Approximate ratios (2026 models)OpenAI Tokenizer (tiktoken)Anthropic Token CountingGoogle Gemini Tokenization
Long-Term Capital Gains Tax Brackets/capital-gains/crypto-profitAnnual2026-09-032026 tax yearIRS Pub 550 — Investment Income & Expenses
Mortgage Interest Rates & PMI/mortgage-calculatorManual review2026-09-036.71% default (Freddie Mac PMMS 30yr fixed, 2026-09-03)Freddie Mac — Primary Mortgage Market Survey
Net Investment Income Tax Thresholds/capital-gains/crypto-profitManual review2025-01-01Not inflation-indexed ($200K/$250K since 2013)IRC §1411 — Net Investment Income Tax
Password Strength Analysis Methods/password-strengthManual review2026-06-01Analysis methods — no expirationNIST SP 800-63B — Digital Identity GuidelinesHave I Been Pwned — Breach Database
Payment Processor Fee Rates/payment-compareManual review2025-06-01As of 2025 (fees subject to change)Stripe PricingPayPal Merchant FeesSquare PricingWise Business Pricing
Pedigree Registry Certificate Formats/pedigree-lookupManual review2026-06-012026 registry formatsAKC — American Kennel ClubThe Kennel Club (UK)TICA — The International Cat AssociationCFA — Cat Fanciers' Association
QR Code Specification (ISO/IEC 18004)/qr-logo-genManual review2026-06-01QR Code standard — no expirationISO/IEC 18004 — QR Code Spec
Reseller Platform Fee Rates/reseller-profitManual review2025-06-012026 platform feeseBay Seller FeesPoshmark FeesMercari FeesEtsy Seller Fees
Schema.org Structured Data Specification/ai-schema-generatorAnnual2026-06-01Schema.org v26.0 (2026 release)Schema.org — Full Type HierarchyGoogle Search Central — Structured DataGoogle Rich Results Test
Shopify Plan Pricing & Payment Rates/dropship-profitManual review2025-06-012026 Shopify feesShopify Pricing PlansShopify Payments Rates
Social Media Image Dimensions 2026/social-resizerMonthly2026-06-012026 platform dimensionsSprout Social — Social Media Image Sizes
Social Security Wage Base/self-employment-tax/freelancer-tax/1099k-taxAnnual2026-07-262026 tax yearSSA — Social Security Wage Base
Standard Deductions/w2-vs-1099/self-employment-tax/freelancer-tax/1099k-tax/capital-gains/crypto-profit/dropship-profitAnnual2026-09-032026 tax yearIRS Rev. Proc. — Annual Inflation Adjustments
State & Local Sales Tax Rates/sales-taxAnnual2026-08-172026 rates (avgLocal/maxLocal are pure local rates, NOT combined)Sales Tax Institute — State RatesAvalara — State & Local Rates
State Income Tax Rates (Progressive Brackets)/w2-vs-1099/self-employment-tax/crypto-profit/freelancer-tax/1099k-tax/dropship-profit/reseller-profit/payroll-tax-calculator/quarterly-tax-reminderAnnual2026-06-182025-2026 tax year (progressive brackets where applicable)Respective state Department of Revenue websitesTax Foundation — State Income Tax Rates
State Non-Compete Agreement Laws (50 States + DC)/non-compete-checkerAnnual2026-06-012026 state non-compete laws (verified Jan-Jun 2026)NCSL — Non-Compete AgreementsFair Competition Law — 50-State SurveyEconomic Policy Institute — Non-Compete Reform
State Tax Reciprocity Agreements/payroll-tax-calculator/multi-state-taxAnnual2026-07-112026 reciprocity agreementsRespective state Department of Revenue websites — reciprocity agreements
Subscription Cancellation Templates/cancel-subscriptionManual review2026-06-012026 template formatsFTC — Cooling-Off Rule
TextRank Summarization Algorithm/pdf-text-extractManual review2026-06-01Algorithm-based — no expirationTextRank: Bringing Order into Texts (Mihalcea & Tarau, 2004)
Time Zone Database (IANA)/timezone-converterMonthly2026-06-01IANA tzdata 2026aIANA Time Zone Database
Tip Calculator — Sales Tax & Tipping Norms/tip-calculatorAnnual2026-01-012026 state sales tax rates & standard tipping normsSales Tax Institute — State RatesETiquette Scholar — Tipping Guide
US Economic Nexus Thresholds by State/nexus-checkerAnnual2026-01-012026 thresholds (verified Jan 2026)Avalara — Economic Nexus State GuideWayfair ruling — South Dakota v. Wayfair (2018)State revenue department websites
Visa Bulletin — Priority Date Cutoffs/green-card-priority-dateMonthly2026-06-01June 2026 Visa Bulletin (DOS published May 2026)U.S. Dept. of State — Visa BulletinUSCIS — When to File AOS
W-4 Withholding Tables & Brackets/w4-calculatorAnnual2026-01-012026 tax yearIRS — Form W-4IRS — Withholding Tables (Pub 15-T)

Data is for estimation and informational purposes only and does not constitute tax, legal, or financial advice. Verify critical figures against the linked official sources before acting on them.