356 tools · free · no sign-up
Developer tools that run in your browser
Most tools process your data locally — FFmpeg, JWT, LLM prompts, PDFs, crypto, images, SEO and more. A few network tools use a small server relay for live requests. All free, no sign-up, no API key.
Browse by category
AI & LLM
23 tools
Tokens, prompts, RAG and tool schemas
JSON
17 tools
Format, validate and convert JSON
Text & String
37 tools
Count, convert, clean and compare text
HTML & CSS
32 tools
Formatters and visual CSS generators
Images
28 tools
Compress, convert and generate images
SEO
10 tools
Previews, meta tags and structured data
Converters
32 tools
Convert between data formats and units
Encoders & Crypto
20 tools
Encode, decode, hash and encrypt
Generators
10 tools
Generate IDs, data and boilerplate
Date & Time
16 tools
Timestamps, timezones and durations
Network & IP
24 tools
IP, subnets, headers and URLs
Color
8 tools
Convert, mix and check colors
Math & Numbers
17 tools
Calculators and number utilities
Security
16 tools
Audit secrets, headers and policies
PDF & Documents
9 tools
Read, split and convert documents
Video & Media
10 tools
Trim, compress, convert and download video
Dev Utilities
47 tools
Everyday developer helpers
Popular tools
See allBackground Remover
Images
Erase the background from a photo and export a transparent PNG.
Online Notepad
Text & String
A distraction-free notepad with multiple notes that auto-save in your browser.
M3U8 / HLS Downloader
Video & Media
Download an .m3u8 HLS stream and save it as a single MP4 file.
JSON Formatter
JSON
Pretty-print and beautify JSON with custom indentation.
Word Counter
Text & String
Count words, characters, sentences, and reading time.
DNS Lookup
Network & IP
Query A, AAAA, MX, TXT, NS, CNAME and other DNS records for any domain.
Screen Recorder
Dev Utilities
Record your screen, window or tab with optional microphone audio.
Online Video Player (M3U8 / HLS)
Video & Media
Play M3U8 (HLS), MP4, WebM and local video files right in the browser.
Meme Generator
Images
Add classic top and bottom captions to any image and download the meme as PNG.
Private by design
Your data never leaves the tab. No uploads, no accounts, no tracking of what you paste.
Works offline
Tools run on browser APIs, so they keep working once the page has loaded.
Instant results
No round-trips, no spinners. Output updates as fast as you type.
Curated collections
Frontend Toolkit
Everything a frontend developer reaches for daily: CSS generators, HTML formatters, JSON utilities and image optimisation.
Backend Toolkit
Payload wrangling for API work: JSON formatting, validation, conversion and text transformation.
Android Toolkit
Assets and payloads for Android development: icon and image generation, JSON handling and colour utilities.
DevOps Toolkit
Config and payload tools for pipelines: YAML and JSON conversion, diffing, minification and validation.
SEO Toolkit
Everything needed to ship a well-optimised page: SERP previews, meta tags, structured data, robots.txt and sitemaps.
UI/UX Toolkit
Visual generators for designers who ship code: gradients, shadows, glassmorphism, radius, waves and colour palettes.
Recently added
Email & URL Extractor
Text & String
Pull emails, links, domains and phone numbers out of any text.
Image to SVG Vectorizer
Images
Trace PNG or JPG images into clean, scalable SVG paths.
Pomodoro Timer
Date & Time
Focus timer with customisable work sprints and breaks.
Punycode / IDN Converter
Network & IP
Convert internationalised domain names to punycode and back.
Web Performance Analyzer
Network & IP
Measure TTFB, page size, compression, caching and resource counts for any URL.
URL Redirect Chain Analyzer
Network & IP
Trace every redirect hop with status codes, timing and the final URL.