Listing Writer: a 270M Gemma in your browser that writes eBay listings that sell

A developer built Listing Writer, a single-page web app that turns a short item description into a formatted eBay or Facebook Marketplace listing using a 270M-parameter Gemma 3 model running entirely in the browser via Transformers.js, with no server or API key. In a test with a Sony WH-1000XM4 headset, the app produced a 52-character title, description, item specifics and pricing guidance without inventing brand, model or price details. The developer notes the first prompt version merely paraphrased input and exceeded the 80-character title limit until a full format example was added.

Listing Writer is a single-page web app that turns a 30-second item description into a polished eBay / Facebook Marketplace listing. You add a photo, the brand, the condition, and any flaws — a 270M-parameter Gemma 3 running entirely in your browser Transformers.js, no server, no API key writes you back: Each section has a copy button. Paste straight into eBay. Live demo: https://qife422.github.io/listing-writer/ https://qife422.github.io/listing-writer/ Code: https://github.com/qife422/listing-writer https://github.com/qife422/listing-writer Resellers. I did a cross-border e-commerce internship this summer AI solutions for product selection and listing SOPs , and I'm gearing up to sell secondhand goods on eBay and Facebook Marketplace myself. Listing writing is the most tedious, most skipped step in resale: bad titles bury your item in search, vague descriptions invite returns. A tool like this earns its keep two ways: it saves ~10 minutes per listing, and better titles measurably get more views. For a seller moving 20 items a week, that's an afternoon back — or the difference between listing and not listing. My first user is me. I fed the app the spec for a test item — a Sony WH-1000XM4 wireless headset, black, like new, light scratches on the earcup, with the original case and cable — and it wrote back, in one pass: Title 52 characters Sony WH-1000XM4 Wireless Headphones Black - Like New Description Like-new Sony WH-1000XM4 in black with light scratches on the earcup. Includes the original case and cable. Item specifics Brand: Sony, Model: WH-1000XM4, Color: Black, Condition: Like new Pricing guidance Check 3 sold listings for this model in like-new condition and price slightly below their average for a faster sale. It didn't invent a single brand, model number, or price, and hitting Rewrite gave the same four-section format instead of echoing my input back. Honest footnote: the first prompt version just paraphrased what I typed and blew past the 80-char title limit, so I taught the prompt with a full format example and re-ran. The pipeline held; the prompt needed the lesson. Three reasons, all economic: onnx-community/gemma-3-270m-it-ONNX via Transformers.js 4.2.0, fp32 the fp16 WebGPU path overflows on this model — learned that the hard way in Week 1 .