DEV Community: WEIGONG GAO

How I Built a Free AI Translator in a Weekend Using Next.js and AI APIs

WEIGONG GAO — Thu, 11 Jun 2026 12:11:26 +0000

I needed a quick translation tool for multilingual content. Existing options like DeepL charge $9/month. So I built one in a weekend.

The Problem

Every translation tool I found either:

Required a paid subscription for decent usage
Had clunky interfaces with ads everywhere
Didn't support the languages I needed

What I Built

A free AI-powered translator at aisense.top/tools/ai-translator that:

Supports 10+ languages out of the box
Uses AI for context-aware, natural translations
Has zero signup requirement
Works instantly in the browser

Tech Stack

Frontend: Next.js + Tailwind CSS
AI Engine: Direct API integration with LLM
Deployment: Vercel + Cloudflare

Key Decisions

No auth required - friction kills conversion. Users can translate immediately.
Server-side AI calls - keeps API keys secure, no CORS issues.
Minimal UI - just a text box and language selector. Nothing else.

Results

The tool handles 10+ languages with surprisingly good quality thanks to modern LLMs. The context-awareness of AI translations beats traditional statistical methods.

What's Next

Adding more language pairs
File upload for batch translation
Browser extension for in-page translation

Try it free: https://aisense.top/tools/ai-translator

Would love feedback from fellow devs!

I Built AI Sense — A Free Directory of 80+ AI Tools You Can Use Directly

WEIGONG GAO — Wed, 10 Jun 2026 23:36:40 +0000

Hey DEV community! 👋

I got frustrated with AI tool directories that just list tools with links — you still have to navigate elsewhere to actually use them. So I built AI Sense, a free directory where you can use 80+ AI tools directly on the site.

What is AI Sense?

AI Sense is a curated directory of AI-powered tools covering:

Writing — Cold emails, blog headlines, text summarizer, AI humanizer
E-commerce — Product descriptions, Amazon listing optimizer, SEO meta tags
Translation — AI translator supporting 10 languages
Developer Tools — Markdown to social card, code explainer
Foreign Trade — Customs declaration, payment terms advisor, quality inspector
And 70+ more...

Key Features

✅ Use tools directly — No redirects, no signups needed for basic use
✅ 10 languages — English, Chinese, Spanish, Japanese, Portuguese, German, French, Korean, Russian, Arabic
✅ Daily updates — New tools and AI news added every day
✅ Free tier — Anonymous users get 3 uses/day, logged-in users get 30/day

Tech Stack

Frontend: Next.js 15 + Tailwind CSS
AI: GLM-5 (Zhipu AI) for tool generation
Auth: Supabase + Google OAuth
Hosting: Vercel + Cloudflare
DB: Supabase (PostgreSQL)

What I Learned Building This

Next.js SSR is crucial for SEO — Google needs server-rendered content to index tool pages
AI tool economics are tricky — Free tier with rate limiting is the only sustainable model
i18n from day one — Building multi-language support from the start saved massive refactoring later
Directory sites need differentiation — "Use it here" vs "link to somewhere else" is the key differentiator

What's Next

Working on a TradeAI-specific platform at trade.aisense.top for cross-border e-commerce workflows
Adding more AI-powered tools weekly
Building BYOK (Bring Your Own Key) mode so power users can use their own API keys

Would love your feedback! Check it out at aisense.top and let me know what tools you'd like to see next.

How I Built a Free AI Text Summarizer That Condenses Any Document in Seconds

WEIGONG GAO — Wed, 10 Jun 2026 18:23:18 +0000

I was spending $15/month on summarization tools just to condense long articles and meeting notes. So I built my own — for free.

The Problem

Every day, we consume more information than we can process. Long emails, research papers, meeting transcripts, news articles — we need summaries, but the tools that do this well charge $10-20/month.

The Solution

I built a free AI-powered text summarizer that works in your browser:

Paste any text — articles, emails, documents, research papers
Choose summary length — short, medium, or detailed
Get instant results — key points highlighted automatically
10+ languages supported
No signup — just paste and summarize

Try it: aisense.top/tools/text-summarizer

How It Works (Technical)

The tool uses a straightforward architecture:

Frontend: Next.js with React — clean UI with real-time preview
AI Processing: Calls an LLM API with a carefully tuned prompt that extracts key sentences and restructures them into a coherent summary
No auth layer: Deliberately no login to reduce friction — makes it instant to use
Deployed on Vercel for edge performance globally

The prompt engineering is the key — I spent time tuning it to preserve factual accuracy while reducing verbosity by 60-80%.

Part of a Bigger Project

This summarizer is one of 200+ free tools I've built at AI Sense. Other tools include:

JSON Formatter & Validator
Regex Tester
OCR Text Extractor
QR Code Generator
Code Explainer
And many more...

All free, no signup required.

What I Learned

Prompt engineering matters — the difference between a good and bad summary is 90% in the prompt
Friction kills adoption — removing signup increased usage by 10x
Free tools can still build an audience — traffic compounds when people share useful tools

What's Next

Batch summarization (paste multiple documents)
Export to PDF/Markdown
Browser extension for one-click summarization

If you find this useful, I'd love to hear how you use it! What kind of documents do you summarize most often?

I Built 30+ Free AI Tools for Amazon Sellers - No Signup Required

WEIGONG GAO — Tue, 09 Jun 2026 13:13:28 +0000

TradeAI: Free AI Tools for Cross-Border E-Commerce Sellers

As an Amazon seller myself, I got tired of paying $99-$279/month for tools like Helium 10 and Jungle Scout just to write better listings. So I built TradeAI - a completely free, no-signup-required suite of 30+ AI-powered tools.

What's Inside

Core Tools (Already Live)

Listing Builder - Generate complete Amazon listings: title, 5 bullet points, description, and backend search terms. Just describe your product.
FBA Fee Calculator - Calculate referral fees, fulfillment fees, and monthly storage costs by category and size tier. Q4 rates included.

Coming Soon (28 More Tools)

Title Optimizer
Bullet Points Generator
Review Analyzer
Keyword Research
Profit Calculator
Competitor Analyzer
HS Code Lookup
Shipping Cost Estimator
Currency Converter
Listing Translator
Customer Email Writer
Ad Copy Generator
And 17 more...

Why Free?

Most Amazon seller tools charge $50-$300/month. The AI-powered listing features? Always behind a paywall. We believe every seller deserves access to AI tools regardless of budget.

Tech Stack

Next.js 15 + TypeScript
Tailwind CSS
ZhipuAI GLM-4-Flash (free AI model)
Open source on GitHub

Who Is This For?

New Amazon sellers on a tight budget
Experienced sellers who want AI-powered listing optimization
Dropshippers doing product research
Anyone doing cross-border e-commerce

Try It Out

Visit trade.aisense.top - no signup, no credit card, just tools.

Star us on GitHub: github.com/CainGao/tradeai-platform

What tools would you like to see next? Drop a comment below!