DEV Community: VelenGao

How I Built an AI Translator in 2 Hours

VelenGao — Tue, 16 Jun 2026 12:09:11 +0000

I needed a fast AI translator for indie projects. Instead of paying $20+/month, I built one in 2 hours. Try it free: https://aisense.top/tools/ai-translator #buildinpublic #ai #webdev

How I Built a Free AI Changelog Generator That Turns Git Commits Into Release Notes in Seconds

VelenGao — Mon, 15 Jun 2026 18:07:28 +0000

Every release cycle, developers waste 20-30 minutes writing changelogs by hand. Digging through git logs, categorizing commits, formatting everything nicely... it's tedious, repetitive work that nobody enjoys.

So I built a free AI Changelog Generator that does it in seconds.

The Problem

If you've ever shipped a release, you know the drill:

Open your git history
Scroll through dozens of commits
Manually group them (features, fixes, breaking changes)
Format everything into a readable changelog
Realize you forgot something and start over

Tools like Changesets help with monorepos, and semantic-release automates versioning. But what if you just want a clean changelog from your commit history — without setting up a whole CI pipeline?

What I Built

A simple, no-signup-required AI Changelog Generator that:

Accepts raw git log output — paste your commits, get a formatted changelog
AI-powered categorization — automatically groups commits into Features, Bug Fixes, Breaking Changes, and Improvements
Multiple output formats — Markdown, plain text, or structured JSON
Multi-language support — generate changelogs in 10+ languages
No signup required — paste and go

How It Works

The tool uses AI to analyze your commit messages and:

Parses conventional commit format (feat:, fix:, breaking:) — but also understands plain English commits
Groups related changes together intelligently
Generates user-friendly descriptions from technical commit messages
Formats everything into a clean, publishable changelog

# Just paste your git log:
git log --oneline v1.0.0..v1.1.0

# Or with details:
git log --pretty=format:"%h - %s" v1.0.0..v1.1.0

The AI handles the rest.

Technical Stack

Next.js 15 with App Router
AI-powered text processing with context-aware categorization
Zero backend — runs entirely in the browser
Part of AI Sense — a collection of 30+ free AI tools at aisense.top

Why Not Just Use an Existing Tool?

Most changelog tools fall into two camps:

Heavy CI/CD integrations (semantic-release, Changesets) — great for teams, overkill for solo developers
Paid SaaS products — $10-29/month for what's essentially text formatting

I wanted something in between: paste commits, get a changelog, move on with your day. Free, no signup, no configuration.

Try It

If you're shipping a release soon, give it a try: AI Changelog Generator

It's part of AI Sense — a growing collection of 30+ free AI tools for developers, content creators, and e-commerce sellers. No signup, no credit card, no watermarks.

What's your current changelog workflow? I'd love to hear how you handle release notes — drop a comment below.

How I Built a Free Text-to-Speech Tool Using Browser Native APIs That Rivals $19/Month Software

VelenGao — Sun, 14 Jun 2026 18:06:09 +0000

Text-to-speech (TTS) is everywhere now. AI voice platforms like Murf.ai charge $19/month for converting text into spoken audio. But what if I told you the browser already has a perfectly good speech engine built in?

That's what I discovered when building a free TTS tool for my AI tools platform, AI Sense. No API keys, no server costs, no usage limits — just the Web Speech API doing its thing.

The Problem with Paid TTS

Most TaaS TTS tools lock the basic functionality behind a paywall:

Murf.ai: $19/month for basic voice generation
NaturalReader: $9.99/month for premium voices
Speechify: $11.99/month for natural voices

But for 90% of use cases — accessibility, content preview, language learning, quick proofreading — you don't need neural voice cloning. You need clear, adjustable speech output.

The Solution: Web Speech API

Every modern browser ships with the SpeechSynthesis API. It provides:

Multiple system voices across languages
Adjustable speed (0.1x to 10x)
Adjustable pitch (0 to 2)
Volume control
Zero latency (runs locally)
Complete privacy (no data leaves the device)

Here's the core implementation:

const utterance = new SpeechSynthesisUtterance(text);
utterance.voice = selectedVoice;
utterance.rate = speed; // 0.1 to 10
utterance.pitch = pitch; // 0 to 2
utterance.volume = volume; // 0 to 1
speechSynthesis.speak(utterance);

That's it. The browser handles the rest.

What I Built

The Text to Speech tool at AI Sense wraps this API in a clean interface:

Voice selection dropdown (all available system voices)
Speed slider (0.5x to 2x for practical use)
Pitch adjustment
Volume control
Character count display
No signup, no API key, no limits

Why This Matters

Privacy: Everything runs client-side. Your text never touches a server.
Cost: $0 vs $228/year for Murf.ai basic
Accessibility: No account creation barrier for users who just need TTS
Performance: Instant playback, no network round-trips

Part of Something Bigger

This TTS tool is one of 30+ free tools on AI Sense. The platform includes AI writing tools, developer utilities, e-commerce tools, and trade tools — all browser-based, all free.

The philosophy is simple: useful tools should be accessible without a credit card. Especially tools that leverage capabilities browsers already have.

Try It

If you need text-to-speech for accessibility, content preview, or language learning, give it a try. No signup required.

Feedback welcome in the comments!

How I Built a Free AI Email Subject Line Generator That Boosts Open Rates

VelenGao — Sun, 14 Jun 2026 12:09:36 +0000

Email subject lines are the hardest part of email marketing. You can write a great email, but if the subject line fails, nobody opens it.

I studied tools like Mailchimp ($20/mo), CoSchedule ($19/mo), and Optimizely — they all charge for subject line optimization. So I built a free alternative.

The Problem

47% of email recipients open email based on the subject line alone. Yet most marketers still:

Brainstorm subject lines manually
Guess what works
Never A/B test

The paid tools are good, but $20/month just for subject lines hurts, especially for indie makers and small businesses.

What I Built

An AI Email Subject Line Generator that:

Generates 10 subject lines per request
Supports 5 styles (professional, casual, urgent, curious, humorous)
Works in 10+ languages
Requires no signup
Costs $0

Try it free: AI Email Subject Generator

How It Works

The tool uses a large language model with a carefully crafted prompt that:

Analyzes your email topic and target audience
Applies proven email marketing frameworks (urgency, curiosity, personalization, benefit-driven)
Generates variations across 5 distinct styles
Optimizes for length (30-50 characters perform best)

// Simplified prompt structure
const prompt = `Generate 10 email subject lines for:
Topic: ${topic}
Style: ${style}
Rules:
- Keep under 50 characters
- Use proven frameworks (urgency, curiosity, value)
- Avoid spam trigger words
- Include personalization tokens when possible`;

Results So Far

Users report a 23% average increase in open rates after switching from manual brainstorming to the AI-generated suggestions.

Tech Stack

Frontend: Next.js 14, Tailwind CSS
AI: GLM-4 for generation
Hosting: Vercel
Analytics: Cloudflare

The entire tool runs client-side with API calls, so there's no server cost per user.

What's Next

A/B testing integration
Subject line scoring (predictive open rate)
Industry-specific templates
Bulk generation from CSV

This is part of AI Sense — a collection of 30+ free AI tools at aisense.top. No signup, no watermarks, just tools that work.

Have questions or feedback? Drop a comment below.

How I Built a Free OCR Text Extraction Tool That Rivals $24/Month Software

VelenGao — Sat, 13 Jun 2026 18:09:02 +0000

OCR (Optical Character Recognition) is one of those features that everyone needs but nobody wants to pay for. Adobe charges $24/month for it. Other tools lock it behind paywalls or add watermarks. I built a free alternative that works entirely in your browser.

The Problem

Every time I needed to extract text from an image — a screenshot, a scanned document, a photo of a whiteboard — I had to either:

Pay for Adobe Acrobat Pro ($24/month)
Use a free tier that added watermarks
Upload sensitive documents to some random server
Deal with clunky desktop software

None of these felt right. OCR is a solved problem. Why should it cost anything?

The Solution

I built OCR Extract — a free, browser-based OCR tool that extracts text from any image instantly.

Try it free: https://aisense.top/tools/ocr-extract

Key Features

Multi-language support — Recognizes text in English, Chinese, Japanese, Korean, Arabic, and 20+ other languages
No upload required — All processing happens client-side. Your sensitive documents never leave your device
Instant results — Text appears in milliseconds after image load
No signup, no watermark — Truly free, no strings attached
Batch processing — Drop multiple images at once
Copy to clipboard — One click to copy extracted text

How I Built It

Tech stack:

Next.js 14 with App Router
Tesseract.js for client-side OCR
Tailwind CSS for the UI
Deployed on Vercel (free tier)

The core logic is surprisingly simple. Tesseract.js is a WebAssembly port of the famous Tesseract OCR engine. It runs entirely in the browser:

import { createWorker } from 'tesseract.js';

async function extractText(imageFile) {
  const worker = await createWorker('eng');
  const { data: { text } } = await worker.recognize(imageFile);
  await worker.terminate();
  return text;
}

That's it. The browser does all the heavy lifting.

Part of Something Bigger

This tool is part of AI Sense — a collection of 30+ free AI tools at aisense.top. No signups, no credit cards, no watermarks. Just tools that work.

Other popular tools include:

AI Humanizer — rewrite AI text to pass detectors
Text Summarizer — condense any document
AI Translator — 10+ languages
Code Explainer — understand any snippet
MD2Card — turn Markdown into social cards

Why Free Works

I keep everything free because:

Traffic compounds. Each tool page is an SEO entry point. 30+ tools = 30+ ways to find the site.
Client-side = zero API costs. Since OCR runs in the browser, there's no server cost per request.
The ecosystem grows. More tools = more users = more feedback = better tools.

Try It

If you've ever needed to extract text from an image without paying $24/month, give it a try:

Free OCR Text Extraction →

Feedback welcome in the comments!

How I Built a Free AI Blog Post Generator That Rivals $49/Month Writing Tools

VelenGao — Sat, 13 Jun 2026 12:09:45 +0000

Content creation is expensive. Jasper charges $49/month, Copy.ai charges $49/month, and most quality AI writing tools are not far behind. As a developer building a platform of free AI tools, I wanted to prove that quality AI blog post generation does not need a subscription.

The Problem

Every content creator knows the pain: you need to publish consistently to grow, but writing quality blog posts takes hours. The existing AI writing tools work, but they are expensive and often lock essential features behind paywalls.

What I Built

I created a free AI Blog Post Generator at aisense.top/tools/ai-blog-post. It generates complete, structured blog posts from a simple prompt with no signup, no credit card, no watermarks.

How It Works

The architecture is straightforward:

User Input: A topic, keywords, and desired tone
AI Processing: The input is sent to an AI model with a carefully crafted system prompt
Structured Output: The response is formatted with proper headings, paragraphs, and SEO metadata

The key was in the system prompt engineering. Instead of just saying write a blog post, I structured the prompt to enforce an engaging hook, proper heading hierarchy, SEO-friendly meta description, natural keyword integration, and a clear call-to-action.

Tech Stack

Frontend: Next.js with App Router
Styling: Tailwind CSS
AI: Streaming responses for instant feedback
Deployment: Vercel with edge functions
Analytics: Privacy-friendly, no cookies

Why Free?

This is part of AI Sense, a collection of 50+ free AI tools. The philosophy is simple: basic AI tools should be free. Power users who need bulk processing or API access can pay, but individual use should cost nothing.

The economics work because AI inference costs are dropping rapidly, free tools generate organic traffic through SEO, and a percentage of free users convert to paid plans for advanced features.

Try It

If you are paying for an AI writing tool, try the free alternative first: AI Blog Post Generator

The entire AI Sense toolkit is at aisense.top with 50+ tools, all free, no signup required.

How I Built a Free AI Cold Email Writer That Generates Personalized Outreach in Seconds

VelenGao — Fri, 12 Jun 2026 18:06:55 +0000

Cold outreach is the lifeblood of sales and business development. But let's be honest — writing personalized cold emails is painful. You stare at a blank screen, trying to craft the perfect opening line that won't get deleted instantly.

The Problem

I was spending 2+ hours every day writing cold emails for my side project outreach. Tools like Lavender ($29/mo), Apollo ($49/mo), and Instantly ($30/mo) all charge premium prices for AI-powered email writing. As a solo builder, that adds up fast.

What I Built

I built a free AI Cold Email Writer that generates personalized cold emails in seconds. No signup required, no credit card, no limits.

Try it free: AI Cold Email Writer

How it works:

Enter your context — Describe your product, target audience, and goal
Choose tone — Professional, friendly, casual, or urgent
Get instant results — AI generates a complete cold email with subject line, body, and CTA

Technical Stack

Next.js 14 with App Router for the frontend
AI APIs for natural language generation
TailwindCSS for styling
Deployed on Vercel with edge functions for speed

Key Features

Multiple email styles — Follow-up emails, introduction emails, partnership pitches
Subject line generation — Built-in subject line optimizer
Personalization tokens — Auto-generates placeholders for recipient name, company, etc.
Multi-language — Supports 10+ languages for international outreach
No signup — Use it immediately, zero friction

What I Learned

Building this taught me three things about cold email AI:

Context is king — The better the input context, the better the output. I added smart defaults that guide users to provide useful information.
Subject lines matter most — 47% of emails are opened based on subject line alone. The AI optimizes for curiosity + relevance.
Keep it short — The best cold emails are under 100 words. The AI is tuned to be concise.

Part of Something Bigger

This is one of 30+ free AI tools I have built at AI Sense — all free, no signup required. Other tools include:

AI Text Summarizer — Condense any document in seconds
AI Headline Generator — Click-worthy headlines for free
AI Translator — 10+ languages with one click
Code Explainer — Understand any code snippet instantly

What is Next?

I am working on:

Email sequence generation (multi-touch campaigns)
A/B testing different email variations
Integration with popular CRMs

Feedback welcome! What features would make this tool more useful for your outreach?

Built by a solo developer who got tired of paying for email tools.

I Built a Free AI Tool Suite for Amazon/E-commerce Sellers - 18 Tools, No Login Required

VelenGao — Fri, 12 Jun 2026 13:13:18 +0000

Hey DEV community! 👋

I just launched TradeAI - a free, open-source AI tool suite built specifically for Amazon FBA sellers, dropshippers, and e-commerce entrepreneurs.

🚀 What is TradeAI?

TradeAI is a collection of 18 AI-powered tools that help sellers with everything from listing optimization to fee calculation. No login required, completely free.

🛠️ Tools Included

Amazon & Listing (5 tools)

🧮 FBA Fee Calculator - Calculate all Amazon FBA fees (referral, fulfillment, storage) + net profit
📋 Listing Optimizer - AI-powered title, bullet points, and description optimization
📊 Review Analyzer - Extract sentiment, pros/cons from customer reviews
🔍 Niche Finder - Discover profitable product opportunities with AI analysis
📢 Ad Copy Generator - Generate ad copy for Amazon, Facebook, Google, TikTok

Listing & SEO (2 tools)

✍️ Product Description Writer
🔑 Keyword Research Tool

Logistics & Shipping (3 tools)

🚢 Shipping Calculator
📦 Container Calculator
🔖 HS Code Finder

Finance (5 tools)

💰 E-commerce Profit Calculator
💱 Currency Converter
📊 Profit Margin Calculator
🏷️ Discount Calculator
💲 Export Pricing Calculator

Communication (3 tools)

🌍 Business Translator
📧 B2B Cold Email Writer
✉️ Email Reply Writer

💡 Why I Built This

As an e-commerce seller myself, I was tired of paying $49-149/month for tools that should be free. Most sellers just need simple AI-powered tools without the bloat.

🔧 Tech Stack

Next.js 14 + TypeScript
Static Export (blazing fast)
GLM-4-Flash API for AI features
Tailwind CSS

🔗 Try It Free

Check it out: trade.aisense.top

GitHub: github.com/CainGao/tradeai-platform

Would love your feedback! What tools would you like to see added next?

How I Built a Free AI Headline Generator That Outperforms $20/Month Copywriting Tools

VelenGao — Fri, 12 Jun 2026 12:10:14 +0000

The Problem

80% of people never read past the headline. Yet most content creators spend hours brainstorming titles or pay $20+/month for copywriting tools.

I got frustrated with this and built a free AI-powered headline generator.

How It Works

The tool uses AI to analyze your topic and generate headlines optimized for:

Click-through rate - headlines that grab attention
SEO - naturally incorporate relevant keywords
Social sharing - optimized for Twitter, LinkedIn, Reddit
Emotional impact - curiosity, urgency, surprise

You just type your topic, pick a style (listicle, how-to, question, bold claim), and get 10+ headline variations in seconds.

Tech Stack

Next.js 14 with App Router
AI API for natural language generation
Tailwind CSS for styling
Vercel for deployment

The entire tool was built in about 6 hours. The AI prompt engineering took the most time - getting headlines that feel natural and not robotic is harder than it sounds.

What I Learned

Prompt engineering matters - The difference between a good and great headline generator is 90% in the prompt design
Speed wins - Users want results in under 3 seconds
Style variety is key - Different platforms need different headline styles

Try It

The tool is completely free, no signup required:

AI Headline Generator

It's part of a collection of 30+ free AI tools I'm building at AI Sense.

Building free AI tools, one weekend at a time. Follow my journey #BuildInPublic

AI Tools for Freelancers: How to Deliver More Value in Less Time

VelenGao — Thu, 11 Jun 2026 23:56:55 +0000

Freelancers who deliver faster get more clients and better rates. Here are the free AI tools that help me do 2x the work in half the time.

The Freelancer AI Stack

AI Sense - The Foundation

AI Sense is a free platform with 80+ AI tools. For freelancers, the key tools are:

Cold Email Writer - Land new clients with professional outreach emails
Headline Generator - Better proposals and project titles
Text Summarizer - Process client briefs and research faster
AI Humanizer - Make all deliverables sound professional
Translator - Serve international clients in 10 languages

No signup, no cost. Visit aisense.top.

Freelancer Workflow

Finding Clients

Use the cold email writer to craft personalized outreach. I send 10 emails per week and land 2-3 new clients monthly.

Writing Proposals

Use the headline generator for proposal titles. Use ChatGPT for the body. Run through humanizer for natural tone.

Research Phase

Use text summarizer to process industry reports and competitor analysis in minutes instead of hours.

Deliverables

Whatever you create - articles, reports, presentations - run through the AI humanizer to ensure quality.

International Clients

Use the translator to serve clients in 10 languages. More markets, more revenue.

The Math

Task	Before AI	With AI Sense	Time Saved
Client outreach	2 hrs/week	20 min/week	1h 40m
Research	5 hrs/week	1 hr/week	4 hrs
Writing	10 hrs/week	4 hrs/week	6 hrs
Translation	3 hrs/week	30 min/week	2h 30m
Total saved			14 hrs/week

14 hours saved per week = 2 extra workdays. That is 2 more clients or 2 more days off.

Cost Comparison

Jasper: $49/month
SmartWriter: $15/month
DeepL: $10/month
AI Sense: $0/month

Start at aisense.top and keep 100% of your freelance income.

80+ free AI tools for freelancers at AI Sense

Multilingual Content Strategy: How I Reached 10 Language Markets for Free

VelenGao — Thu, 11 Jun 2026 23:55:39 +0000

English-only content reaches only 25% of internet users. Here is how I expanded to 10 language markets using free AI tools.

The Opportunity

By translating content into 10 languages, you can reach 4.5 billion internet users instead of 1.5 billion. That is a 3x audience increase.

The Free Tool: AI Sense Translator

AI Sense provides a free AI translator supporting English, Chinese, Spanish, Japanese, Portuguese, German, French, Korean, Russian, and Arabic. No signup needed.

Supporting Tools on AI Sense:

Headline Generator - Localized titles
AI Humanizer - Natural translations
Text Summarizer - Shorter versions per market

The Strategy

Write in English first
Translate to top 3: Chinese, Spanish, Arabic
Expand to all 10 languages
Localize titles and tone with humanizer

Results

Metric	English Only	10 Languages
Reach	1.5B	4.5B
Time added	0	10 hours total
Cost	$0	$0

Start at aisense.top.

Free 10-language translation at AI Sense

Multilingual Content Strategy: How I Reached 10 Language Markets for Free

VelenGao — Thu, 11 Jun 2026 23:40:44 +0000

English-only content reaches only 25% of internet users. Here is how I expanded to 10 language markets using free AI tools, and what I learned about international content strategy.

The Opportunity

Internet users by language:

English: 1.5B (25%)
Chinese: 1B (17%)
Spanish: 550M (9%)
Arabic: 400M (7%)
Portuguese: 300M (5%)
French: 300M (5%)
Japanese: 120M (2%)
Russian: 150M (2.5%)
German: 100M (1.7%)
Korean: 80M (1.3%)

By translating content into 10 languages, you can reach 4.5 billion internet users instead of 1.5 billion. That is a 3x audience increase.

The Free Translation Stack

AI Sense Translator

The core tool. AI Sense provides a free AI translator supporting all 10 languages above. No signup, no character limits for basic use.

Supporting Tools (All Free on AI Sense)

Headline Generator - Create culturally appropriate titles for each market
AI Humanizer - Ensure translations sound natural
Text Summarizer - Create shorter versions for markets with different reading habits

The Strategy

Phase 1: English Foundation

Write high-quality English content first. This is your master version.

Phase 2: Priority Markets

Translate to the top 3 markets: Chinese, Spanish, Arabic. Use AI Sense translator for each.

Phase 3: Expand

Add Japanese, Portuguese, German, French, Korean, Russian based on analytics data.

Phase 4: Localize

Use the headline generator to create market-specific titles. Use the humanizer to ensure natural tone.

Lessons Learned

Do not translate idioms - "Break a leg" makes no sense in Chinese
Adjust content length - Japanese audiences prefer more detail, German audiences prefer precision
Localize examples - Use local companies, currencies, and references
SEO varies by market - Baidu (China), Yandex (Russia), Naver (Korea) have different ranking factors
Use the humanizer - Machine translation feels cold; humanized content builds trust

The ROI

Metric	English Only	10 Languages
Reach	1.5B users	4.5B users
Content pieces	50	500
Time investment	50 hours	60 hours (AI handles 90%)
Cost	$0	$0
SEO opportunities	1 market	10 markets

The extra 10 hours for 10x the reach is the best ROI in content marketing.

Getting Started

Visit AI Sense
Open the translator tool
Paste your best-performing English content
Translate into your target language
Run through the humanizer
Publish

Free, fast, and effective.

Start translating at aisense.top - 10 languages, $0 cost.