Free online tools
A free suite of utilities you can use without an account. Most tools run entirely in your browser (no paste to our servers). The HTML price checker can fetch public URLs with a rate limit so you can debug selectors — read each page for limits. Want the same work automated on a schedule? See how CloudyBot runs agents, browsers, and tasks.
JSON formatter & validator
Format, minify, or validate JSON instantly. Runs locally in your browser — ideal for API responses and config files.
Open tool →Regex tester
Test JavaScript regular expressions with live matching and capture groups.
Open tool →URL encoder & decoder
Encode or decode URI components, encode full URIs, and parse URLs into protocol, host, path, query, and hash — special characters handled in your browser.
Open tool →Password generator
Set length and character sets (uppercase, lowercase, numbers, symbols), see a strength meter, and copy a cryptographically random password — all in your browser.
Open tool →Markdown preview
Side-by-side Markdown editor with live HTML preview — built-in converter, no external libraries, everything stays in your browser.
Open tool →Diff checker
Compare two texts with a line-by-line diff: removals and additions highlighted, summary counts, optional live compare — all in your browser.
Open tool →JWT decoder
Decode JWT header and payload in your browser. Signature shown for reference only — not cryptographically verified.
Open tool →Base64 encoder & decoder
Encode UTF-8 text or small files to Base64, or decode Base64 to text — client-side only, optional file up to 2 MB.
Open tool →Hash generator (SHA & HMAC)
SHA-256, SHA-384, SHA-512, optional SHA-1, plus HMAC-SHA — UTF-8 text or file up to 2 MB, hex or Base64 output. Web Crypto in your browser.
Open tool →Email subject line generator
Generate 8–12 subject line ideas for campaigns, cold outreach, newsletters, or follow-ups — pick tone and goal, runs in your browser.
Open tool →AI cost calculator
Estimate public LLM API spend vs CloudyBot’s published plan caps — presets, blends, embeddings sketch, and shareable links. Runs locally.
Open tool →AI token counter
Paste text for a word-based token estimate and list-price dollars for major API models — sortable table, TSV export, optional reply cost. Runs locally.
Open tool →Who these tools are for
Developers and operators use the data and crypto utilities (JSON, JWT, Base64, hashes) for debugging APIs, configs, and webhooks. Marketers and founders use the email subject helper and AI cost or token tools to sanity-check copy length and rough spend before committing to a vendor. Anyone scheduling work can translate cron into plain English and preview next runs. Tools are free to use without an account; the full CloudyBot product adds scheduled agents, browser sessions, and published plan caps.
For a tour of every utility with links to source and blog context, see free online developer tools (2026).
More tools (browser-backed URL checks and other utilities) are on the roadmap.