⚡ 93+ tools · 🔐 runs in your browser · 🆓 free
A web toolbox for everyone
for devs, AI users, teachers & the office — runs 100% in your browser, no signup needed.
Browse by job-to-be-done
93 tools grouped by the work you do — click a group to see them all.
🤖 AI / LLM
6 tools Token, cost, prompts, model comparison — daily LLM workflows
🎯 Token Counter 📜 Markdown Preview 🆚 AI Model Comparison
🧑💻 Programming / Dev
38 tools JSON, JWT, regex, SQL, cURL, CIDR, Mermaid, commits — daily dev toolkit
🔐 JWT Decoder 🆚 Text Diff 🧩 JSON Schema Generator
📦 Data & Time
3 tools CSV diff, time zones, working days — data & calendar utilities
📅 Working Days Calculator 📑 CSV Diff 🌍 World Time Zone Converter
📝 Text & Markdown
8 tools Slug, case, regex, count, sort, lorem, MD table/TOC, SQL — text utilities
🔑 Password Generator 🔤 Remove Vietnamese diacritics 🔗 URL Slug Generator
🎨 CSS & Design
13 tools Color, gradient, shadow, animation, grid, clip-path — visual builders
🎨 Color Picker ✨ CSS Animation Builder 🪞 CSS Filter Builder
🖼️ Image & Media
4 tools Compress, base64, placeholders, QR — 100% client-side
📱 QR Code Generator 🖼 Lorem Picsum URL Builder 🗜️ Image Compressor
🇻🇳 VN & personal utilities
12 tools Salary, tax, loans, BMI, FX — VN-specific
💰 VN Loan & Deposit Calculator 💼 VN Salary Calculator 🎲 Random Number Generator
👩🏫 Classroom
9 tools Timer, attendance, group maker, grading — teacher daily tools
📊 Grade Average Calculator 🎲 Random Picker 👥 Group Maker
🔥 Trending
The most-used and top-rated tools
HOT HOT HOT HOT HOT
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Token Counter
Accurate token count for ChatGPT, Claude, Gemini, Llama. Live input cost.
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Grade Average Calculator
Weighted average, VN-scale classification, distribution chart.
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VN Loan & Deposit Calculator
Deposit + loan repayment, decreasing & flat rate, full amortization.
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Password Generator
Cryptographically secure random passwords with entropy meter, custom char classes.
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VN Salary Calculator
Vietnam 2026: SI 8%, HI 1.5%, UI 1%, progressive PIT, personal + dependent deductions.
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API Cost Calculator
Estimate monthly/yearly LLM API spend. Compare which model is cheapest.
🆕 New
Recently added to TopDev
NEW NEW NEW NEW NEW NEW
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Markdown → HTML Export
Convert Markdown to standalone HTML for blog publishing, email, or WordPress. 3 CSS themes (GitHub, clean, none) + dark mode + .html download.
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CSS Clip-path Generator
12 shape presets (triangle, star, hexagon, speech bubble…) plus editable polygon points. Live preview, copy CSS.
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Compound Interest Calculator
Compound interest growth: initial principal + monthly contributions. Year-by-year table with total interest earned.
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TDEE / BMR Calorie Calculator
BMR (Mifflin-St Jeor) and TDEE by activity level. Calorie targets for cut/maintain/bulk + macro split (protein/carbs/fat).
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Number to Words
Convert numbers to Vietnamese (mốt, tư, lăm, lẻ) or English words. Up to 999 trillion. Optional "đồng" / "VND" suffix for contracts.
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Discount Calculator
Final price after a discount (% or fixed), stacked extra discount + voucher, with VAT.
Learn AI on TopDev
Beyond the tools, a fast AI reference in Vietnamese.
📖 AI terms
Open glossary (34) →- What is AI Alignment?The research field that works to keep AI acting in line with human intent and values — even as systems grow more powerful.
- What is a Context Window?The maximum amount of text an LLM can 'remember' in a single pass. It decides how much information you can fit into a prompt.
- What is a Diffusion Model?A class of AI model that generates images by gradually denoising — the technology behind Midjourney, Stable Diffusion, and DALL-E.
- What is Computer Vision?The branch of AI that lets machines 'see' and interpret images and video — from face recognition to self-driving cars.
📰 Latest posts
Read more →- Welcome to TopDevOur launch post — why we built this, what's coming, and how you can get involved.
- How to write effective prompts: 7 rules every beginner should knowLearn 7 simple rules that will make ChatGPT/Claude answer more accurately and on-target right away.
- Install Claude Code and write code with AI in 30 minutesStep-by-step guide: install Claude Code, sign in, and ask the AI to write your first code.
Why TopDev?
A simple, safe, free web toolbox.
⚡
No signup
Use it right away — no account, no email.
🔐
In-browser, local-first
Your data stays on your device. Works offline.
🇻🇳
Plain Vietnamese, real examples
Hand-written, no machine translation, VN-specific examples.
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Free forever
No ads, no paywall, no freemium traps.