Guides
ガイド
ブラウザ上でファイルを安全に扱うための実践的なガイドとインサイト。各記事から直接ツールへアクセスできます。
How to Generate a Strong Password — Stop Memorizing, Start Generating
How to create passwords that resist guessing, and why it works. Generated with cryptographic randomness, never stored or transmitted anywhere.
How to Reduce Video File Size — Even to an Exact 25MB (In Your Browser)
Practical ways to shrink large videos that keep hitting messenger, email, and upload limits — re-encoded inside your browser, with an honest note on big files.
How to Make a Karaoke Track (Remove Vocals from a Song) with AI, in Your Browser
Make a backing track for karaoke practice or covers. An AI source-separation model runs inside your browser — no upload — and you get the isolated vocals too.
How to Open HWP Files Without Hancom Office (Mac, Windows, Phone)
How to read Korean HWP documents without installing Hancom Office — a browser viewer with no upload, plus print and save-to-PDF. Rendering limits stated honestly.
How to Remove a PDF Password — With the Password You Know (In Your Browser)
Turn a PDF that demands a password on every open into a plain PDF. Both the file and the password stay inside your browser — nothing is sent to a server.
How to Convert iPhone HEIC Photos to JPG (When They Won't Open on Windows)
iPhone photos arriving as HEIC and refusing to open? Convert them to JPG or PNG — dozens at once, inside your browser, without uploading them anywhere.
How to Play a Video with SMI or SRT Subtitles (Without Broken Korean Text)
Got a video and a separate SMI/SRT subtitle file? Overlay them in a browser player — it auto-detects the legacy EUC-KR encoding common in Korean SMI files, and lets you nudge sync in 0.5s steps.
How to Make an ID Photo from a Selfie — Sized and Background-Ready
Turn a phone photo into a properly sized ID photo — background removed and replaced with a standard color, cropped to spec, and your face photo never leaves your device.