30 tools · Free · No sign-up
Free developer, AI and SEO tools
that run in your browser
Convert data formats, count LLM tokens, generate schema markup and clean up text — without uploading a single byte to a server. Every tool here does one job, loads fast and works the moment the page opens.
Private by design
Almost every tool runs entirely client-side. Your data is parsed in the browser tab and never transmitted.
No accounts, no limits
No sign-up wall, no daily quota, no watermark and no paid tier holding back the useful half.
Built to be fast
Plain HTML, CSS and JavaScript. No framework payload, no tracking scripts, no cookie banner.
See the tools in action
Every tool runs in your browser. Nothing you paste is uploaded to a server.
Data Format Converters
Convert between JSON, YAML, CSV, XML and TypeScript in your browser. Every converter validates as you type and nothing is uploaded to a server.
JSON to YAML Converter
Turn JSON into clean, readable YAML in the browser.
Open tool →YAML to JSON Converter
Convert YAML config files into valid JSON, instantly.
Open tool →CSV to JSON Converter
Turn spreadsheet exports into clean JSON arrays.
Open tool →JSON to CSV Converter
Flatten JSON arrays into spreadsheet-ready CSV.
Open tool →XML to JSON Converter
Parse XML feeds and SOAP responses into workable JSON.
Open tool →AI & LLM Tools
Count tokens, estimate API costs, check context window limits and generate llms.txt. Practical utilities for anyone building on GPT, Claude or Gemini.
AI Token Counter
Estimate how many tokens your prompt will cost before you send it.
Open tool →LLM API Cost Calculator
Work out what your AI feature will cost per call and per month.
Open tool →Context Window Calculator
Check whether your document fits — and how much room is left to answer.
Open tool →llms.txt Generator
Publish a map of your site for AI crawlers and answer engines.
Open tool →JSON Schema Generator
Turn a sample JSON document into a validation schema.
Open tool →SEO & Web Tools
Generate robots.txt, meta tags, schema markup and UTM links, preview your SERP snippet and validate an XML sitemap. Technical SEO essentials, free.
Robots.txt Generator
Build a correct robots.txt, including rules for AI crawlers.
Open tool →Meta Tag Generator
Generate title, description, Open Graph and Twitter card tags.
Open tool →SERP Snippet Preview
See how your page will look in search results before you publish.
Open tool →Schema Markup Generator
Build valid structured data for rich results.
Open tool →UTM Campaign URL Builder
Build tagged links that report cleanly in analytics.
Open tool →Text & String Tools
Compare two texts, test regular expressions, build URL slugs, convert case and count words and characters. Fast, private, browser-based text utilities.
Diff Checker
Compare two texts and see exactly what changed.
Open tool →Regex Tester
Test a regular expression and see what each part of it does.
Open tool →URL Slug Generator
Turn any title into a clean, readable URL slug.
Open tool →Case Converter
Convert text between sentence, title, camel, snake and kebab case.
Open tool →Word Counter
Count words, characters, sentences and reading time as you type.
Open tool →Encoding & Developer Tools
Base64, URL encoding, JWT decoding, hash generation and UUIDs. The small developer utilities you reach for several times a week, all client-side.
Base64 Encoder & Decoder
Encode and decode Base64, including URL-safe and file input.
Open tool →URL Encoder & Decoder
Percent-encode and decode URLs and query parameters.
Open tool →JWT Decoder
Inspect a JSON Web Token's header, claims and expiry.
Open tool →Hash Generator
Generate cryptographic hashes for text or files.
Open tool →UUID Generator
Generate cryptographically random UUIDs in bulk.
Open tool →Image & Asset Tools
Convert images to Base64 data URIs, inline SVGs, read EXIF metadata, generate favicons and extract colour palettes — all in the browser.
Image to Base64 Converter
Turn an image into a data URI you can inline in HTML or CSS.
Open tool →SVG to Data URI Converter
Inline SVGs in CSS at a fraction of the Base64 size.
Open tool →EXIF Metadata Viewer
See what a photo reveals — camera, settings, and location.
Open tool →Favicon Generator
Produce every favicon size and the HTML to go with it.
Open tool →Colour Palette Extractor
Pull the dominant colours out of any image.
Open tool →Guides and tutorials
Longer reads on the formats, tokens and markup these tools deal with.
Common questions
Are these tools really free?
Yes. All 30 tools are free with no account, no sign-up and no usage limit. There is no paid tier holding back features.
Is my data uploaded to a server?
For the large majority of tools, no. Conversion, encoding, hashing and counting all run in your browser using JavaScript, so the text or file you paste never leaves your device. Any tool that does need a server request says so plainly on its own page.
Do the tools work offline?
Once a tool page has loaded, the client-side tools keep working without a connection, because the processing happens locally rather than on a server.
Can I use the output commercially?
Yes. Whatever you convert, generate or encode belongs to you, and there is no attribution requirement.