23 private utilities
A sharper desk for everyday dev work.
Format JSON, decode JWTs, test regex, compress images, and generate passwords without an account. Every tool runs in the browser, so files and secrets stay on this device.
Library
23
Small tools, each with its own page and shortcuts.
Privacy
Local
Parsing, hashing, and conversion stay on this device.
Speed
Live
Output updates as you type. Copy or download in one click.
Free online developer tools
KeptTools is a library of browser tools for formatting, encoding, and everyday image work. Open a page, do the job, and leave. Nothing you paste or drop in is uploaded, and there is no account to create.
Start with the JSON formatter, the image compressor, or the JWT decoder. The sections below list every tool. More about the project is on the about page.
01
Data & Converters
02
Encoders & Security
01
JWT Decoder
→Inspect JWT header, payload, and signature locally — secrets never leave your machine.
02
Base64 Encoder / Decoder
→Encode and decode Base64 text or convert images to Base64 data URIs instantly.
03
Hash Generator
→Generate MD5, SHA-1, SHA-256, and SHA-512 hashes instantly in your browser.
04
URL & HTML Encoder
→Encode or decode URL components and HTML entities with one click.
05
Password Generator
→Create strong random passwords locally with length and character-set controls.
03
Formatters
01
JSON Formatter & Validator
→Beautify, minify, validate, and explore JSON with instant error highlighting — 100% in your browser.
02
SQL Formatter
→Beautify messy SQL queries with consistent indentation and keyword casing.
03
HTML Formatter
→Beautify messy HTML with consistent indentation, or minify it to one line.
04
Text
01
Word Counter
→Count words, characters, sentences, and reading time as you type — entirely in the browser.
02
Case Converter
→Convert text to sentence case, lower, upper, title, camel, snake, and kebab case.
03
Lorem Ipsum Generator
→Generate placeholder paragraphs, sentences, or words for mockups and layouts.
05
Image Tools
01
Image / WebP Converter
→Compress images and convert PNG/JPEG/SVG to WebP entirely in the browser.
02
Image Compressor
→Compress an image toward 1 MB or a custom size, then compare and download the result.
03
Image Cropper
→Crop with a free frame or common aspect ratios, preview the result, and download a PNG.
04
Image to SVG
→Turn an image into an SVG made of traced shapes, or wrap the original picture in an SVG file.
05
Change Image Background
→Replace a portrait background with white, blue, gray, a custom color, or transparency. The person stays unchanged.
06
Web & CSS
07
DevOps & Utilities
01
Regex Tester & Explainer
→Live regex matching with flags and visual highlight of every match.
02
Cron Expression Generator
→Build cron schedules visually and read them as plain English.
03
UUID & Slug Generator
→Generate bulk UUID v4 values and clean URL slugs from any text.
04
Unix Timestamp Converter
→Convert Unix timestamps to readable dates and turn a date into epoch seconds.
Next step
Two ways to start, both private.
Open a tool and work in the browser. Nothing from these pages is uploaded.