If you've ever had seven different browser tabs open — one for a JSON formatter, another for a Base64 encoder, a third for a regex tester, and four more for various finance calculators — this post is for you.
I built UtilsDaily.com to solve this exact problem: one fast, free, no-login place for the tools I reach for every single day.
Here's everything that's inside.
What is UtilsDaily?
UtilsDaily is a free utility platform with 170+ tools for developers, students, and finance planners. The core philosophy is simple:
- Zero login required — use any tool instantly
- Privacy-first — no tracking, no cookies beyond what's needed
- No ads — clean interface, always
- Embeddable — every tool has a free iframe embed for your blog or docs site
The tools span eight categories. Let me walk through each one.
🛠️ Developer Tools
This is where I spend most of my time. A few standouts:
JSON Formatter & Validator
Paste in any JSON and it'll:
- Format/beautify with 2-space, 4-space, or tab indent
- Minify for production (removes all whitespace)
- Validate and show parse errors with clear messages
- Show key count and file size
Quick tip from the docs — JSON is typically 30–50% smaller than equivalent XML, which is why it won the API format wars. The validator catches the most common mistakes: single quotes, trailing commas, and undefined values (which aren't valid JSON — use null).
SQL Formatter
Paste in that dense production query and get back something a human can actually read. Supports CTEs, window functions, JOINs — everything from your messy SELECT to your monstrous stored procedure.
Regex Tester
Live regex testing with match highlights. I use this more than I'd like to admit.
Other dev tools worth bookmarking:
| Tool | What it does |
|---|---|
| UUID Generator | Cryptographically random UUID v4 |
| Hash Generator | MD5, SHA-1, SHA-256 in the browser |
| JWT Decoder | Inspect header, payload, signature |
| Password Generator | Secure random passwords |
| Unix Timestamp Converter | Epoch → human-readable and back |
| Ruby to JSON Converter | Ruby hash syntax → valid JSON |
| Image to Base64 | Data URI strings for CSS/HTML |
| CSS Box Shadow Generator | Visual builder with live preview |
| CSS Border Radius Generator | Rounded corners, visually |
| CSS Gradient Generator | Linear + radial with live preview |
Formatters & Minifiers
For the days when you inherit badly formatted code:
- XML Formatter — indent and validate XML
- HTML Formatter — beautify HTML
- YAML Formatter — format + convert YAML to JSON
- CSS Formatter — readable CSS from minified soup
- CSS Minifier + JS Minifier — strip whitespace for production
CSS Converters
Two I use constantly for responsive design:
- PX to REM Converter — design in pixels, output in REM
- PX to EM Converter — based on parent font-size
- Aspect Ratio Calculator — for video embeds, image containers
🎓 Interview Preparation Guides
This section is unique — it's not just a tool, it's a deep reference.
Ruby & Rails Interview Prep (16 topics)
Covers everything that actually comes up in backend interviews:
-
Metaprogramming —
define_method,method_missing,class_eval -
Blocks, Procs & Lambdas — key differences with the
&operator explained -
Eager Loading & N+1 Queries —
includesvseager_loadvspreload - Rails Design Patterns — Service Objects, Query Objects, Policy Objects, Decorators
- Background Jobs — Sidekiq, SQS, Kafka compared in a decision table
- SQL Fundamentals — CTEs, window functions, JOINs with runnable examples
- Hotwire/Turbo — the Rails 7+ stack explained
-
Action Cable & WebSockets — real-time with
broadcast_append_to
Each topic has actual runnable code examples, not just theory. The search bar lets you jump to any concept instantly.
Redis Interview Prep (16 topics)
Data types, persistence modes (RDB vs AOF), pub/sub, clustering, and caching patterns with code.
React Interview Prep (12 topics)
From fundamentals to senior-level concepts — hooks, reconciliation, performance patterns.
Ruby Multithreading Guide (14 topics)
Threads, the GIL, Mutex, Fibers, Ractor, deadlocks, and real-world concurrency patterns. Essential reading before any senior Ruby interview.
💰 Finance Tools — India
This is the largest section, built specifically for Indian users. If you're an Indian developer (like me) who also invests, you'll know the pain of switching between five different government portals just to run basic calculations.
Investment Calculators
- SIP Calculator + Step-up SIP — with annually increasing contributions
- Lumpsum Calculator
- PPF Calculator — with tax benefits
- SSY Calculator — Sukanya Samriddhi Yojana
- ELSS Calculator — tax saving under 80C
- CAGR Calculator + XIRR Calculator — true returns on irregular cash flows
Tax & Salary
- Income Tax Calculator — Old vs New regime comparison — this one saves the most arguments
- GST Calculator — inclusive and exclusive
- Salary Calculator — CTC to take-home
- HRA Calculator — tax exemption
- EPF Calculator + VPF Calculator
- Gratuity Calculator — on resignation or retirement
Loans & Comparison Tools
- EMI Calculator — home, car, personal loans
- Flat vs Reducing Rate Comparison — banks love quoting flat rates
- Prepay vs Invest Calculator — settle the eternal debate
- Buy vs Rent Calculator
Stocks & Trading
- Brokerage Calculator — Equity, Intraday, and F&O charges
- Capital Gains Calculator — LTCG and STCG on equity
- MF Capital Gains
💵 Finance Tools — US
Three fully updated tools for 2026:
- 401(k) Calculator — with 2026 contribution limits and employer match
- Paycheck Calculator — federal, FICA, all 50 state taxes
- Mortgage Calculator — PITI with PMI, taxes, insurance
- Debt Payoff Calculator — Avalanche vs Snowball strategy comparison
- Self-Employment Tax Calculator — with the deductible half
✏️ Text Tools
The text manipulation tools that belong in every developer's bookmarks:
- Text Diff — side-by-side comparison with highlights
- Markdown Editor — live preview
- Word Counter — words, chars, sentences, paragraphs
- Remove Duplicates — line deduplication
- Find and Replace — with regex support
- Prefix & Suffix Adder — bulk line operations
- Case Converter — UPPER, lower, Title, camelCase
- Lorem Ipsum Generator
🎲 Converters, Health, & Random Tools
Unit Converters: Length, weight, temperature, area, speed, data storage, volume, and number base (binary/octal/decimal/hex).
Health & Fitness: BMI, body fat %, calorie needs (TDEE), macro calculator, sleep cycle calculator, pregnancy due date calculator.
Date & Time: Age calculator, timezone converter (20 cities), Pomodoro timer, business days calculator, week number calculator.
Random: Random number generator, coin flip (cryptographically secure), dice roller (D4–D20), list randomizer, random color generator.
Color: Color picker (HEX/RGB/HSL), color palette generator using color theory, gradient generator.
🔌 Embed Any Tool on Your Site
Every tool on UtilsDaily has an embed option. One line of HTML:
<iframe
src="https://utilsdaily.com/developers/json-formatter?embed=true"
width="100%"
height="500"
frameborder="0"
style="border: 1px solid #e2e8f0; border-radius: 8px;"
title="JSON Formatter & Validator">
</iframe>
Attribution back to UtilsDaily is included as a small footer link — that's how the project stays free.
Why I Built It
I'm a backend engineer with experience across Ruby on Rails, Golang, and blockchain infrastructure. Over time I found myself with the same eight tabs open every day — JSON formatter, base64 tool, regex tester, EMI calculator, income tax comparison — each on a different site, each with ads, each requiring a separate bookmark.
UtilsDaily started as a personal utility page that grew into something bigger. The interview prep section came directly from my own prep work — I couldn't find a single page that covered Ruby metaprogramming, Rails design patterns, SQL fundamentals, and Redis in one place with actual runnable code examples. So I built it.
What's Coming Next
- More US finance tools (Roth IRA, Social Security estimator — already live)
- API documentation checker
- GraphQL query formatter
- Color contrast accessibility checker (WCAG)
- More interview prep guides: System Design, PostgreSQL, Golang
Try It
Everything is at utilsdaily.com — no login, no ads, 170+ tools.
If there's a tool you reach for daily that's missing, drop it in the comments. I read everything and the backlog is community-driven.
Built with a focus on Developers and Finance planning (India, US), but the dev tools are universally useful. Happy to answer any questions about the tech stack or specific tools in the comments.
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