Free tools that just work.
Fast, simple utilities for converting, calculating, formatting, generating, and creating — directly in your browser. No signup. No uploads. No tracking.
Private by design
Files and text are processed in your browser and never uploaded. Turn off your network and every tool still works.
Fast and free
No signup, no paywalls, no waiting. Tools load instantly from a global edge network.
Simple
Each tool does one thing well. No clutter, no dark patterns, no modal traps. You land, you use it, you leave.
Popular tools
The most-used tools on Uttir. Click any to open it instantly.
JSON Formatter
Format, beautify, and validate JSON with adjustable indentation — instantly in your browser.
Developer Tools
UUID Generator
Generate cryptographically random UUID v4 identifiers, one or a thousand at a time.
Developer Tools
Base64 Encoder
Encode any text — including emoji and non-Latin scripts — into standard Base64.
Developer Tools
JWT Decoder
Decode a JWT’s header and payload and check its expiration — without sending it anywhere.
Developer Tools
JWT Sign (HS256 / RS256)
Sign a JSON Web Token with HS256 (HMAC shared secret) or RS256 (RSA private key). Output is a standard compact JWT (header.payload.signature).
Security Tools
HMAC Generator
Compute a Hash-based Message Authentication Code (HMAC) for any message and shared secret. Supports SHA-256, SHA-512, SHA-1, and MD5. All computation runs in your browser.
Security Tools
Regex Tester
Test and debug regular expressions with live matches, capture groups, and highlighted results.
Developer Tools
Word Counter
Count words, characters, sentences, and paragraphs in your text instantly.
Text Tools
Percentage Calculator
Three percentage tools in one: percent of a value, ratio as a percent, and percent change.
Calculators
Newest tools
recently addedYouTube Thumbnail Downloader
Get every thumbnail size YouTube generated for a public video — pick the resolution you want and download. Free, in your browser, no signup.
Media Tools
SVG Optimizer
Minify and clean up SVG markup from any source — strip editor metadata, remove default attributes, round numbers, and see the byte savings. Free, in your browser, no upload.
Image Tools
Background Remover
Remove the background from any image — entirely in your browser. The first run downloads a small local model (~25 MB); after that it runs offline and nothing is uploaded.
Image Tools
Browse by category
199 tools across 19 categories. Pick a category to see everything in it.
Developer Tools
Format, validate, decode, and generate the things developers deal with every day.
69 tools →Text Tools
Count, convert, compare, and clean up text instantly.
41 tools →Calculators
Quick, accurate calculators for percentages, dates, ages, and finance.
45 tools →Color Tools
Pick colors, convert formats, and check accessibility.
10 tools →Image Tools
Convert, compress, and resize images without uploading them.
25 tools →PDF Tools
Merge, split, and convert PDFs locally in your browser.
9 tools →Converters
Convert between formats, units, and standards.
19 tools →SEO Tools
Generate meta tags, sitemaps, robots.txt, and UTM links.
11 tools →File Tools
Work with files directly in your browser.
3 tools →Generators
Generate passwords, IDs, dummy data, and more.
26 tools →Date & Time Tools
Work with dates, times, durations, and time zones.
9 tools →Encoding Tools
Encode and decode Base64, URLs, HTML entities, and more.
12 tools →Data Tools
Transform CSV, JSON, XML, and YAML.
19 tools →Web Tools
Utilities for building and testing websites.
19 tools →Media Tools
Work with audio and video in your browser.
4 tools →Security Tools
Check, generate, and decode security primitives in your browser.
10 tools →Network Tools
Look up IP, DNS, WHOIS, and HTTP headers from your browser.
6 tools →Math Tools
Statistics, equations, sequences, and number theory.
18 tools →AI Tools
AI-powered utilities that run entirely in your browser.
5 tools →From the blog
What Is My IP Address — And What Does It Reveal About Me?
Your IP address is a public identifier that any website you visit can see. Learn what it exposes (city, ISP, ASN, sometimes a VPN), what it does not expose, and how to check yours without uploading anything.
Aug 31, 2026 · 7 min read
How to Create an XML Sitemap (and Why You Need One)
A sitemap.xml file tells search engines which pages on your site exist. Learn what to include, what to leave out, how to write one by hand or generate one, and how to submit it to Google and Bing.
Aug 31, 2026 · 7 min read
How to Test Color Contrast for Accessibility (WCAG 2.2 Explained)
Color contrast is the most-measured accessibility metric on the web. This guide explains the WCAG 2.2 contrast formula, the AA and AAA thresholds, and how to make sure your site is usable for people with low vision.
Aug 31, 2026 · 6 min read
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