I put 64 file tools and an open-weight AI model in a browser tab. Nothing gets uploaded.

说明与用途

在 Android 上，Fizzdoc 的 PDF 分割工具因 qpdf 频繁读取文件而速度慢；通过将文件一次性复制到内存（最多 128 MB）解决了问题，使速度与笔记本相当。

问题

On Android phones, Fizzdoc’s PDF split tool took six minutes due to many small file reads by qpdf, causing poor performance.

结果

Performance on Android improved from six minutes to near‑instant split, matching laptop speed for small files, while maintaining privacy guarantees.

工作流

• Open Fizzdoc on Android
• Select PDF file
• Choose split tool
• qpdf reads file in many small chunks via WORKERFS
• Performance suffers
• Implement copy‑up‑to‑128‑MB logic
• Read file once into memory
• qpdf processes file
• Download result

证据

On a laptop the same kind of job took about a second.

来源

What I didn’t know: qpdf doesn’t ask for a few big pieces. It asks for lots and lots of tiny ones.

来源

On a 10 MB, 28-page test PDF, I counted 1,448 separate reads

来源

Same test file: 1,448 reads became zero, and even on my laptop the split went from 1.4 s to 0.25 s.

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