Browser-first utilities

Online toolbox for developers & ops

Fast, private, browser-first utilities for developers and operators.

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Time & Scheduling Cron Debugger Generate, validate, explain, and preview upcoming runs for Cron expressions. Open tool

Costs & Conversion API Cost Calculator Calculate API costs from input, output, and cached token prices. Estimate per-request and monthly budgets entirely in your browser. Open tool

Time & Scheduling Timestamp Converter Convert Unix seconds and milliseconds to local or UTC ISO dates, and convert ISO dates back to timestamps. Open tool

Time & Scheduling Time Zone Converter Convert a local date and time between IANA time zones with daylight-saving changes handled correctly. Open tool

Networking IP / CIDR Calculator Calculate IPv4 network ranges, host capacity, membership, and bounded subnet previews from an address and prefix. Open tool

Text & Data JSON Formatter Validate, format, minify, and recursively sort JSON in your browser with precise error locations. Open tool

Text & Data Base64 Converter Encode UTF-8 text to Base64 or decode standard and URL-safe Base64 back to text. Open tool

Security & Identity JWT Decoder Decode and inspect compact JWT or JWS headers, payloads, claims, and signatures locally in your browser. Open tool

Web & URLs URL Codec Encode and decode URL components, complete URLs, and form values with batch line processing. Open tool

Text & Data HTML Entity Converter Encode and decode HTML named or numeric character references safely in your browser. Open tool

Security & Identity UUID Generator Generate cryptographically secure UUID v4 and v7 values, validate UUID text, and inspect version, variant, and v7 timestamps locally. Open tool

Security & Identity Hash Generator Generate SHA-256, SHA-384, and SHA-512 hashes for text or local files with hexadecimal or Base64 output. Open tool

SEO & Webmaster SEO Meta Generator Generate escaped title, description, canonical, robots, Open Graph, and Twitter metadata with local search and social previews. Open tool

SEO & Webmaster robots.txt Generator Build, validate, and inspect robots.txt crawler directives locally, including multiple user-agent groups and Sitemap URLs. Open tool

Security & Identity Password Generator Generate random passwords locally with configurable character sets, ambiguity filtering, and batch output. Open tool

SEO & Webmaster Sitemap Generator Generate and validate XML sitemaps from absolute HTTP(S) URLs, with optional last modification dates, change frequencies, and priorities. Open tool

Text & Data QR & Barcodes Generate QR codes or Code 128 barcodes in batches with built-in or pasted JSON label templates, then download PNGs, ZIP, or Excel. Open tool

Text & Data Label Templates Design QR and barcode labels with text, borders, and image backgrounds. Export JSON or send the layout to the batch generator. Open tool

Web & URLs HTML to Markdown Convert pasted HTML or local files to Markdown with headings, lists, tables, and code structure. No webpage fetching or content uploads. Open tool

Text & Data Token Counter Count text tokens locally with o200k_base or cl100k_base. Inspect token pieces, token IDs, and UTF-8 byte counts in your browser. Open tool

Text & Data Markdown to Word Convert Markdown and AI responses into editable Word documents with headings, lists, tables, and code blocks. Generate DOCX locally in your browser. Open tool

Text & Data Prompt Diff Compare two prompt versions by line or character. Inspect additions, deletions, and unchanged text locally in your browser. Open tool

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Browse by use case

Time & SchedulingBuild and inspect time-based rules.NetworkingCalculate and inspect network values.Costs & ConversionCalculate costs from usage and unit prices, and estimate request budgets.Text & DataParse, validate, and transform structured text.Web & URLsInspect and generate web platform and URL values.SEO & WebmasterPlan search and social metadata for websites.Security & IdentityGenerate and inspect security credentials and identifiers.