28 private utilities
Free online developer tools that run in your browser.
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
28
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
→Decode a JWT token in your browser. Read the header and payload locally — the token is never uploaded.
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, paragraphs, 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
PDF Tools
01
Merge PDF
→Combine multiple PDFs into one file in your browser. Reorder pages, then download — nothing is uploaded.
02
Split PDF
→Split a PDF by page ranges or extract selected pages. Download one file or a ZIP of several — all in the browser.
03
Compress PDF
→Reduce PDF file size in your browser by recompressing images. Text and layout stay intact — nothing is uploaded.
04
PDF to JPG
→Convert PDF pages to high-quality JPG images in your browser. Preview pages, then download one file or a ZIP.
05
JPG to PDF
→Turn JPG images into a single PDF in your browser. Reorder pages, set size and margins, then download.
07
Web & CSS
08
DevOps & Utilities
01
Regex Tester & Explainer
→Live regex matching with flags and visual highlight of every match.
02
Cron Expression Generator
→Free cron generator online — build cron expressions 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 a Unix timestamp in seconds or milliseconds to UTC and local time.
Next step
Two ways to start, both private.
Open a tool and work in the browser. Nothing from these pages is uploaded.