GhostConvert

网页右键存的图十有八九是 .webp，拖进 PS 直接打不开。我一般浏览器里本地转成 png 就正常了，文件也不用传出去 https://ghostconvert.cc

录了段会议音频想发同事，手机导出来是 .m4a，对方播放器压根打不开。后来用 https://ghostconvert.cc 在浏览器里转成 mp3，不用来回传文件，几秒完事。

别人发来的 .csv 用 Excel 打开，数字和日期经常挤成一列还乱码，光调分隔符就能折腾半天。我图省事直接在浏览器里转 xlsx，文件不离开本机就完了。https://ghostconvert.cc

前两天帮朋友转一份带身份证扫描件的 PDF，他差点传到一个要注册会员的在线网站。那种网站文件真会落到别人服务器上，挺悬的。后来用浏览器本地转的，文件根本没离开我电脑 https://ghostconvert.cc

同事甩来个 .wps 文件，我这边 Office 双击直接懵。它其实就是金山的老格式，浏览器里就能转成 docx，文件全程不离开本机。顺手存这儿了 https://ghostconvert.cc

手机拍的 .mov 发给安卓朋友打不开，转成 mp4 就通用了。在浏览器里本地转就行，视频不离开本机。https://ghostconvert.cc

做好的 PPT 发给同事，对方电脑没装字体、打开全是乱码排版飞了。先转成 PDF 版式就锁死了，在 https://ghostconvert.cc 上本地转、文件不离开本机。

epub 本质就是个 zip 包了一堆 html，拿解压软件就能扒开。想转成 pdf 慢慢读，浏览器里本地转一下就行，文件不往外传 https://ghostconvert.cc

老板甩来个扫描合同 PDF，二十多兆，邮箱死活发不出去。后来在浏览器里本地压了一下，直接砍掉快一半，文件全程没离开过我电脑 https://ghostconvert.cc

微信发原图动不动十几兆，群里传半天转圈。后来我都在浏览器里把图压一下再发，几兆变几百 K，关键是文件不离开本机，不用丢给那些要登录的压缩网站。 https://ghostconvert.cc

今天才知道 AVIF 这格式，比 WebP 还省空间，手机拍的图小一半还不糊。可惜好多软件还不认，先用 https://ghostconvert.cc 在浏览器里转成 jpg 再发。

报销几张单据想拼成一个 PDF 发给财务，某付费网站非得逼你开会员。后来在浏览器里直接合并，文件不用上传服务器，几秒钟搞定 https://ghostconvert.cc

昨晚帮朋友把一份 80 页的标书 PDF 拆成单独几页，只留报价那几张发过去，本地处理文件不用上传。要拆 PDF 的话可以试试 https://ghostconvert.cc

抠图真的是世纪难题，之前找那些在线工具要么加水印要么逼着开会员。最近发现 ghostconvert.cc 能直接在浏览器里把图片背景去掉，文件也不上传，挺省心。https://ghostconvert.cc

同事甩来一份 PDF 让我改，Word 直接打开全是乱码。后来发现可以直接把 PDF 丢进 https://ghostconvert.cc 转成可编辑的 Word，文件还在本地处理、不用上传，省得来回传网盘了。

以前要把几张截图拼成一个 PDF，我都是先塞进 Word 再导出，结果排版老是乱。后来发现直接把图拖到 https://ghostconvert.cc 就能合成 PDF，顺序自己拖着调，两分钟完事。

iPhone 拍的照片发给同事，对方 Windows 打不开，这事我碰到过好几回。HEIC 在苹果生态里挺省空间，出了这圈就到处碰壁。懒得装插件的话，拖到 https://ghostconvert.cc 转成 JPG 就完事，转换在浏览器里跑，文件不用往服务器传。

Local-first isn't a feature. It's a whole class of problems that just don't exist. No server bill for data you can't see. No 3am panic over a leak. The most reliable infra is the kind you already deleted.

What's the weirdest format you've had to convert? I got a 'PDF' last week that was a renamed Word doc. The file lied about itself and I wasted an hour debugging the wrong thing.

The hardest part of a client-side tool isn't building it. It's that nobody believes it. 'Where does my file actually go?' Nowhere — there's no server. Convincing people a privacy tool is real takes longer than writing the code.

Converted a 1.2GB video in the browser once. The tab didn't error — it just died, silently. Browsers give you the compute but not the RAM you think you own. Client-side has a ceiling, and it's someone else's memory budget.

A file converter is the classic 'weekend project' pitch. Two months later I've learned PDFs can be Word docs in a trench coat, and every camera maker ships its own HEIC flavor. The converter was the easy part. The formats never end.

Six weeks into an AdSense review that still hasn't cleared. The server bill shows up on time every month though. Turns out the "passive" in passive income is just the expenses.

GhostConvert runs fully in your browser, but the wasm is served from Cloudflare Workers. So I went 'serverless' and still get woken by a 4MB cold start at 3am. The server moved. It didn't disappear.

After 3 months GhostConvert is 10% file conversion and 90% 'what do I do when this file is cursed.' Should've named it GhostDebug.

Spent 3 hours smoothing the upload bar animation. Not one person mentioned it. They all mentioned the one format it choked on. Users don't see the polish — they see the single crack.

Spent a day making the converter 2x faster. Then checked the logs: 90% of uploads are a single 200KB file. I'd optimized a bottleneck almost nobody hits. The slow path I shipped is what everyone actually uses.

Made a free file converter. Real business model: one ad in the corner that maybe 1 in 1000 people click. It pays the domain renewal. 'Free for you' just has to mean 'not losing money for me.'

Strangers email to say a tool I built saved them an afternoon. None of it lands anywhere public. The people happiest with it are the ones you'll never see talking about it. The loudest feedback is rarely the truest.

Debugging WASM is the worst part: when the C side crashes, the browser console shows hex, not a stack. I had to write logs into memory and read them back out. Every line is a cross-boundary copy. The fun of low-level work.

Everyone asks 'can you add format X?' Each format is a codec, and codecs are heavy. One more converter is another megabyte of wasm in the bundle. The feature request is free. The download isn't.

My test files are all named test.pdf. Then a user uploaded 'FINAL_invoice_v3_ACTUAL.pdf' that was 400MB and corrupt, and the page just stared at it. Real files aren't polite. The conversion was the easy part.

Got a DM about a file that broke the converter. Normally I'd just open it. But 'your files never leave the browser' is the whole pitch — so I can't. I had to talk them through pasting the error. Privacy is clean until you're debugging a bug inside data you swore you'd never touch.

My converter runs in the browser, so it inherits every browser's quirks. Firefox, Chrome, Safari each ‘open’ a file a little differently. I'm not writing one converter — I'm mediating a three-way argument about what a PDF even is.

Three hours debugging why conversion was slow. Profiled it. The file was fine — the spinner animation was eating the main thread. My "performance problem" was CSS. Fixed one line, and I'm not proud of how long that took.

Someone emailed to say they converted a file on a flight with no wifi. I never built an offline mode. It just worked — GhostConvert runs entirely in the browser, so a metal tube over the ocean is fine. No server to lose connection to. That wasn't a feature. It was a side effect.

“Ship first, fix later” is fine advice until your product is a file converter. A slightly-wrong conversion isn’t a bug you patch Tuesday — it’s someone’s tax document with a missing page. Some tools you actually have to get right before you hit publish.

Shipped the converter. Felt done. Then someone ran a 3GB file on a phone with 2GB free — no error, just a black screen. Most of my real-world bugs aren't logic. They're the device quietly running out of room.

Built it privacy-first: no accounts, no server logs, nothing tracking you. The downside nobody mentions — I now have zero analytics. I genuinely don't know which formats get used most. Just guessing. Flying blind is the quiet tax for not watching your users.

The "free" converter finished my file, then stamped a watermark across it. Turns out the real product was the watermark-removal subscription. I built GhostConvert to just hand your file back, untouched. No stamp, no page 2.

Added 10 languages to the converter. Translating the error strings was easy. The tone — brusque in English, polite in Japanese — is where I gave up and shipped inconsistent vibes. Nobody noticed but me.

Spent more time handling formats browsers refuse to open than writing the conversion itself. HEIC on Windows, AVIF in most browsers. The hard part of a 'simple' converter isn't the math — it's the browser's mood about what a file is even allowed to be.

The safest user data is the data you never collect. My converter has no account, no database, nothing logging your files. Nothing to leak. I never get to write the 'we take your privacy seriously' email — I just built myself out of needing one.

Everyone said put it on a server. Cold starts, autoscaling, timeouts — a whole other job. I shoved the converter into the browser with WASM instead. No server to wake up, ever. Felt like cheating. The architecture nobody pitches you is sometimes the one that works.

What's the weirdest file you've ever had to convert? Someone once sent me a PDF that was secretly a ZIP full of TIFFs. The web is just boxes inside boxes wearing fake extensions.

Spent 3 hours debugging why my WASM ran 10x slower than it should. Turns out I copied the file into memory twice before the conversion even started. One-line fix. The bottleneck was never the algorithm — just me being sloppy with a buffer.

“Free” and “no account” are two different promises. Most free converters still make you sign up first — they want the email more than the conversion. I built GhostConvert so you paste a file and leave. The tool is the product. That's the whole pitch.

Workers 免费额度够跑转换 API，前提是别超内存。128MB 上限，转大文件时盯用量条像盯血压。

Wrote the converter in Chrome. Looked flawless. Then a Safari user sent a screen recording of it melting. Safari handles the file API a hair differently and my WASM choked on it. “Works on my machine” is a lie when your machine is one browser.

Nobody trusts a browser-only converter. They assume there's a server swallowing their file. My favorite demo: pull the wifi mid-convert, it finishes anyway. Then someone asks 'where did my file go?' It was never uploaded.