董子航's profile on Product Hunt

About

Independent developer. 115 days in, 90 tools shipped. Building ToolKnit — a suite of browser-based tools that run 100% locally. No uploads, no accounts, no tracking. Your files never leave your device. Categories: PDF, Image, Video, Audio, Text, Calculators, Timers, Creative, AI, Self-Tests. Currently exploring: AI-powered tools, collaborative features, and keeping everything free. Always open to tool requests and feedback.

Badges

Tastemaker

Gone streaking

Gone streaking 5

Maker History

24pictureAI image studio — generate, transform & upscale to 4K
Apr 2026
RewriteEmailTurn weak emails into winning negotiations with AI
Apr 2026
OohSleep — Sleep Better, FreeFree AI sleep tracker with snoring detection — works offline
Apr 2026
ToolKnit90 browser tools. Zero uploads, 100% private.
Mar 2026

🎉

Joined Product HuntMarch 22nd, 2026

Forums

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24h ago

Built 90 browser tools in 115 days. All zero-upload. Am I crazy?

Hey PH community, solo dev here.

115 days ago I built my first tool a PDF compressor. One rule:

the user's file never leaves their device. No uploads, ever.

That obsession snowballed. 115 days later, 90 tools across 10 categories:

p/toolknit

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1d ago

90 browser tools. Zero uploads, 100% private.

ToolKnit is a suite of 90 free browser-based tools covering PDF,

image, video, audio, text, calculators, timers, creative tools,

AI experiences, and self-tests.

Every tool runs 100% locally in your browser via WebAssembly.

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2mo ago

Two privacy-first tools I built: a browser-based file processor + an AI image studio

Hey Product Hunt community! I wanted to share two tools I've been working on. Both share a common philosophy: you should only pay for what you actually use, and privacy matters. --- **Toolknit** toolknit.com
A completely browser-based file processing toolbox. No uploads, no servers, no account needed. - PDF conversion, compression, merging, splitting
- Image format conversion, compression, cropping, background removal
- Video compression, GIF conversion, audio extraction
- Audio format conversion
- 60+ tools in total, all running locally via WebAssembly Everything processes right in your browser. Your files never leave your device. Free, no signup. --- **24picture** 24picture.com
A credit-based AI image studio. Pay only for what you use credits never expire. - Text to Image with 3 AI models (Nano Banana 2, NB Pro, GPT Image)
- Image to Image transformation
- AI Upscale to 4K
- AI Model photography
- AI Tattoo Design with 7 styles
- AI Sticker Maker
- Photo to Anime
- 9 specialized tools total Free credits when you sign up, no card required. --- Both are live and I'd love your honest feedback. What would you improve? What features would make these genuinely useful for your workflow? Thanks for checking them out!