# Plaintools

> Browser-only utilities. Nothing is uploaded.

All tools run in the browser tab. There is no HTTP API and nothing is uploaded. If you can apply a tool’s markdown recipe locally, do that. If the job needs a file decoder or a filled-in form (HEIC conversion, schema JSON-LD), send the user to the HTML tool instead of guessing.

## Tools

- [Schema markup generator](https://plaintools.io/seo/schema-markup-generator.md): When you need FAQ/HowTo/Article/Product JSON-LD from a form. Client-side; send the user to the HTML tool.
- [UTM generator](https://plaintools.io/seo/utm-generator.md): When you need a tagged campaign URL (source, medium, campaign). Client-side; the recipe is portable.
- [Slug generator](https://plaintools.io/seo/slug-generator.md): When you need a lowercase hyphenated URL slug from a title. Client-side; the recipe is portable.
- [JWT decoder](https://plaintools.io/dev/jwt-decoder.md): When you need to read JWT header/payload claims without verifying. Client-side; the recipe is portable.
- [JSON to CSV converter](https://plaintools.io/dev/json-to-csv-converter.md): When you need CSV from a JSON array of objects (one-level flatten). Client-side; the recipe is portable.
- [YAML to JSON converter](https://plaintools.io/dev/yaml-to-json-converter.md): When you need YAML↔JSON for a config snippet. Client-side; uses js-yaml; the recipe is portable.
- [JSON-LD generator](https://plaintools.io/seo/json-ld-generator.md): When you need the same schema.org JSON-LD types under a JSON-LD name. Client-side; send the user to the HTML tool.
- [HEIC converter](https://plaintools.io/convert/heic-converter.md): When the user must turn a HEIC/HEIF still into JPEG or PNG. Client-side WASM; send them to the HTML tool (or a local converter).
- [Text diff checker](https://plaintools.io/dev/text-diff-checker.md): When you need a line/word diff or a unified patch of two snippets. Client-side; uses npm `diff`; the recipe is portable.
- [IBAN validator](https://plaintools.io/checkers/iban-validator.md): When you need an IBAN checksum and country-length check. Client-side; the recipe is portable. Not a bank confirmation.
- [Seller financing calculator](https://plaintools.io/finance/seller-financing-calculator.md): When you need a seller-note monthly payment, interest, and optional balloon. Client-side; the recipe is portable. Not advice.
- [Deck material calculator](https://plaintools.io/build/deck-material-calculator.md): When you need a rectangular deck takeoff (board count and linear feet). Client-side; the recipe is portable. Estimate only.
- [Hash generator](https://plaintools.io/dev/hash-generator.md): When you need a SHA-256, SHA-384, SHA-512, or SHA-1 hash. Client-side Web Crypto API; the recipe is portable.
- [Timestamp converter](https://plaintools.io/dev/timestamp-converter.md): When you need to convert Unix seconds/ms to ISO 8601 or vice versa. Client-side; the recipe is portable.
- [CSV to JSON converter](https://plaintools.io/dev/csv-to-json-converter.md): When you need a JSON array of objects from CSV text. Client-side; the recipe is portable.
- [Owner financing calculator](https://plaintools.io/finance/owner-financing-calculator.md): When you need an owner-financing payment, loan-to-value, interest, and balloon estimate from the buyer's side. Client-side; the recipe is portable. Not advice.
- [Pool financing calculator](https://plaintools.io/finance/pool-financing-calculator.md): When you need swimming pool financing monthly payment, total interest, and amortization snapshot. Client-side; portable. Not advice.
- [XIRR calculator](https://plaintools.io/finance/xirr-calculator.md): When you need the annualized XIRR percentage from dated cash flows. Client-side pure TS; portable.
- [Roof pitch calculator](https://plaintools.io/build/roof-pitch-calculator.md): When you need roof pitch (x/12), pitch angle, slope percentage, or rafter line length. Client-side; portable. Estimate only.
- [Open Graph generator](https://plaintools.io/seo/open-graph-generator.md): When you need standard Open Graph and Twitter card meta tags snippet. Client-side; portable.
- [Subnet calculator](https://plaintools.io/dev/subnet-calculator.md): When you need IPv4 subnet boundaries, usable host ranges, netmasks, or host capacity from CIDR. Client-side pure TS; portable.
- [Favicon generator](https://plaintools.io/seo/favicon-generator.md): When you need favicon sizes (16/32/48/180/192/512), .ico, and HTML link tags generated from an image. Client-side Canvas; portable.
- [Robots.txt generator](https://plaintools.io/seo/robots-txt-generator.md): When you need to generate robots.txt crawler rules and sitemap directives. Client-side pure TS; portable.
- [Etsy fee calculator](https://plaintools.io/shipping/etsy-fee-calculator.md): When you need to calculate Etsy seller fees, payment processing, and net profit margins. Client-side pure TS; portable. Estimate only.
- [CIDR calculator](https://plaintools.io/dev/cidr-calculator.md): When you need CIDR block boundaries, subnet masks, wildcard masks, usable host ranges, and binary representations. Client-side pure TS; portable.
- [Schema checker](https://plaintools.io/seo/schema-checker.md): When you need to validate JSON-LD syntax and Schema.org field compliance locally. Client-side pure TS; portable. Local checks only.
- [Image compressor](https://plaintools.io/convert/image-compressor.md): When you need to compress image files (JPEG, PNG, WebP) with quality sliders and dimension scaling. Client-side Canvas; send the user to the HTML tool.
- [Break-even calculator](https://plaintools.io/finance/break-even-calculator.md): When you need to calculate break-even units, break-even revenue, contribution margin, and profit volume milestones. Client-side pure TS; portable. Estimate only.
- [GIF compressor](https://plaintools.io/convert/gif-compressor.md): When you need to compress, resize, or optimize a GIF in the browser. Client-side GIF decoding and re-encoding with no uploads.
- [Case converter](https://plaintools.io/text/case-converter.md): When you need text case conversions (lower, UPPER, Title, Sentence, camel, snake, kebab, CONSTANT). Client-side pure TS; portable.
- [Readability checker](https://plaintools.io/text/readability-checker.md): When you need Flesch reading ease, grade level, and readability statistics for English text. Client-side pure TS; portable.
- [Retirement corpus calculator](https://plaintools.io/finance/retirement-corpus-calculator.md): When you need to estimate retirement corpus requirements, inflation-adjusted expenses, and monthly savings needed. Client-side pure TS; portable. Estimate only.
- [PDF to JPG converter](https://plaintools.io/convert/pdf-to-jpg-converter.md): When you need to render PDF pages to JPEG images client-side. Uses pdf.js and JSZip in the browser tab with no uploads.
- [Video compressor](https://plaintools.io/convert/video-compressor.md): When you need to compress MP4, MOV, WebM, or MKV video in the browser. Uses ffmpeg.wasm client-side with no uploads.
- [GST calculator](https://plaintools.io/finance/gst-calculator.md): When you need India GST calculation (inclusive/exclusive, CGST/SGST/IGST, standard 0/5/12/18/28% slabs). Client-side pure TS; portable. Rates illustrative.
- [Hreflang generator](https://plaintools.io/seo/hreflang-generator.md): When you need hreflang link tags, XML sitemap xhtml:link blocks, and reciprocal validation. Client-side pure TS; portable.

## Optional

- [Privacy](https://plaintools.io/privacy): No-upload policy. Tool input never leaves the tab.
- [Terms](https://plaintools.io/terms): Provided as-is. No warranty.
- [HTML homepage](https://plaintools.io): Human-facing catalog of live tools.
- [SEO tools (HTML)](https://plaintools.io/seo): Client-side helpers for structured data, campaign URLs, social meta tags, and clean slugs. Nothing is sent to a server.
- [Dev tools (HTML)](https://plaintools.io/dev): Inspect tokens, generate hashes, convert timestamps, diff text, and convert data formats on your machine. Nothing leaves the tab.
- [Text tools (HTML)](https://plaintools.io/text): Client-side text utilities for case conversion, reading levels, and formatting. Nothing leaves your browser.
- [Convert (HTML)](https://plaintools.io/convert): Turn files into something a Windows box or a CMS can open. Decoding happens in this tab, not on a server.
- [Checkers (HTML)](https://plaintools.io/checkers): Validate identifiers in the tab. IBANs are checksummed here and are not sent anywhere.
- [Finance (HTML)](https://plaintools.io/finance): Rough numbers for notes and investments you already understand. These calculators are not advice.
- [Build (HTML)](https://plaintools.io/build): Material takeoffs and framing calculations you can run on-site. Estimates only; suppliers still cut the real boards.
- [Shipping (HTML)](https://plaintools.io/shipping): Marketplace fee schedules and seller payouts calculated in your browser. Estimates only. Nothing is uploaded.