Sales Tax Lookup is a US sales tax API that finds current sales tax rates for any US ZIP code or two-letter state abbreviation. It returns the jurisdiction state code and the estimated combined tax rate.

Sales Tax Calculator is a US sales tax API that computes the exact sales tax amount and combined rate for purchases in any US state or ZIP code. Paid plans add breakdowns by state, county, city, and special district rates.

Sanctions Screening checks a person or company name against the US Treasury OFAC Specially Designated Nationals (SDN) list. It returns scored matches with aliases, dates of birth, addresses and sanctions programs so you can decide whether to block or review.

I-Bond Rates provides current and historical interest rates for US Series I Savings Bonds. I-Bonds are inflation-protected savings bonds with a composite rate made up of a fixed rate plus an inflation rate that adjusts every 6 months.

Scrabble Word Scorer calculates the official Scrabble score for any word across five languages. It provides the total base points, letter count, and point values for each individual letter.

SEC Filings returns the recent EDGAR filing history for a US public company by ticker - 10-K annual reports, 10-Q quarterlies, 8-K current reports, Form 4 insider filings, S-1 registrations and more - each with its filing date, form type and a direct link to the document, plus derived filing-acti...

Sentiment Analysis evaluates the emotional tone of any text string. It returns an AFINN valence score, a comparative word-normalized score, and a five-tier sentiment label from very negative to very positive.

SEO Data Scraper parses any public URL to collect title tags, meta descriptions, robots directives, and Open Graph or Twitter card previews. Paid plans add canonical URLs to verify indexing rules.

SEO Quick Validator inspects live web pages for on-page SEO errors and tag issues. Pass any URL to inspect title lengths, meta descriptions, H1 headings, viewport and canonical tags, image alt text, and unverified external links.

Shoe Size Converter translates footwear measurements across regional standards, including US, UK, Australian, Mexican, and Korean sizing systems. Provide a size, source region, and gender category to get equivalent sizes, with paid plans adding European, Japanese, and centimeter measurements.

Short Code Generator creates custom alphanumeric short codes for vouchers, referral tokens, and redirect slugs. Specify a length, batch count, and character set like numeric, hex, or Base58 to receive an array of random strings.

Silver Price quotes spot silver prices per troy ounce, gram, and kilogram in US dollars, including 24-hour price change and trend direction. Paid plans can request quotes across 172 currencies, 24-hour high and low ranges, and hourly price snapshots.

Sitemap Generator is a website sitemap generator API that creates valid XML sitemaps from URL lists following the sitemaps.org protocol for search engine optimization.

Slot Machine Simulator generates slot machine reel spins for configurable reels, bet sizes, and spin counts. Every run outputs symbol names and emoji for each reel; paid plans add payout calculations, win tracking, and net profit statistics.

Slugify converts text into clean, URL-friendly slugs with custom separators and optional lowercase formatting. Pass any raw string to get back the original text and its normalized slug with accents stripped and spaces replaced.

Solar Potential calculates solar energy potential for any latitude and longitude coordinates. It returns average daily usable sunlight hours and optimal panel orientation, with paid plans adding yearly totals and cloud factors.

Spam Detector is a spam detection API that evaluates text submissions to determine whether content is likely spam. Pass a message body and an optional sender email to check for spam patterns, with paid plans adding IP blocklist and disposable email checks.

Spell Checker flags misspelled words in submitted English text and generates correction suggestions. It counts total spelling errors and lists possible replacements for each mistaken word.

Spelling Bee Generator creates word puzzles with 7 letters where players form words using a required center letter.

SPF Validator checks the Sender Policy Framework (SPF) DNS record for a domain to verify if it’s valid and optionally whether a given IP address is authorized to send emails for that domain.