Zipda 사용 가이드

What Zipda is

Zipda is an archive and extract app for iPhone, iPad and Mac. The same app is available on iOS and on macOS, linked from a single store page. The promise in its development notes is that filenames do not turn into garbage, files over 4 GB still open, and split archives still open. If you have ever opened a Windows-made archive on an iPhone and seen unreadable filenames, or hit a large archive that would not open, that is the problem this app targets.

Supported formats

• Extract and create: ZIP, 7z and the tar family (tar, tar.gz, tar.bz2, tar.xz)
• Extract only: RAR, LZH, ALZ
• Not supported: EGG files are not supported because of licensing and patent concerns. There is also no RAR creation, since the RAR format cannot be written by third-party apps under its license.

Which formats can be created varies by app version, so check the store description and version notes for the current state.

Screens at a glance

The six images below are store screenshots with a promo headline on top; the screens are the iPhone app. Sample file names and numbers are for demonstration.

Getting started

1. Install and first launch

Install from the store links above. No account is needed. According to the development notes, files are processed on the device, and there are no ads and no tracking.

2. Open an archive

On iPhone, long-press an archive in the Files app and choose Zipda from the share menu, or import a file inside the app. On Mac you can drag a file onto the app window; dropping an archive brings up an extraction confirmation, and dropping several processes them one after another.

3. Browse and extract part of an archive

Before extracting everything you can scan the list, search it, or preview a single file. You can also pull out just one file. Opening, browsing, searching and preview do not count toward the daily limit described below.

4. Open a password-protected archive

Opening an encrypted ZIP, 7z or RAR prompts for the password. The app is designed to handle the traditional ZipCrypto scheme still common in password-protected ZIP files, as well as newer ones.

5. Create an archive

Pick files, folders, or several photos and videos to compress. ZIP can be protected with AES-256, and a Windows-compatible preset helps filenames survive on Windows. ZIP64 archives over 4 GB are handled as well.

Why do Korean filenames garble?

According to the ZIP specification (PKWARE APPNOTE), the filename field is interpreted as UTF-8 only when bit 11 of the general purpose flag is set; otherwise the default is the old IBM code page 437 character set. Yet Korean Windows compression tools long wrote Hangul names as CP949 (EUC-KR family) bytes without setting that bit. The receiving program has no way to know the intended reading, so it decodes the bytes with the wrong rule, such as CP437 or a Western European character set, and produces gibberish such as "ÃÖÁ¾". The struck-through lines on the filename repair screenshot are exactly such names.

The fix is to guess which encoding was originally used. The app analyzes the name bytes and proposes a candidate, and when it is not confident it lets you choose by tapping Change. The screen states that repair changes only names and leaves file contents untouched. The background on encoding trouble and how formats differ is covered separately in ZIP, RAR and 7z formats explained.

Filename repair

Older archive tools often store filenames in a regional encoding rather than UTF-8, such as CP949 or EUC-KR in Korea and Shift-JIS in Japan, so the names look broken when opened elsewhere. Zipda detects the encoding on the device and shows the correct names, and provides a repair tool for names that are already garbled. The development notes record one limitation: very short Japanese filenames can be misread as Korean. If a result looks wrong, try a different encoding.

Split archives

Archives divided into several parts (for example .zip.001 or .z01) are meant to be grouped into one set and opened together. All parts must be in the same folder, and one missing part means it cannot be extracted. This guide covers opening split sets and does not cover creating them.

Pricing and limits

Every feature can be used for free, but extracting and creating are each limited to three runs per rolling 24 hours. Opening, searching, previewing and filename repair are not counted or are unlimited. To remove the limit you can choose an auto-renewing subscription, monthly or yearly; check the price shown in the store. There are no ads.

Transferring with a computer over the same Wi-Fi

The Tools list on the home screen includes "Transfer over the same Wi-Fi". According to the privacy policy, a temporary web server runs on the device only while you have this screen open, and a computer on the same local network connects with a browser to exchange files. Files do not pass through any outside server. As the same document says, though, this connection is plain, unencrypted HTTP, so do not use it on untrusted public Wi-Fi such as cafes or airports; use it only on a network you trust, like home or the office. Closing the screen when you are done, which stops the server, is also a good habit.

Practical tips

• If an archive misbehaves, first check that its size looks right and that every part of a split set is present.
• For recipients on Windows, create with the Windows-compatible preset to reduce filename problems.
• Send the password through a different channel (a phone call, another messenger) than the archive.
• Before unpacking something large, check how much free storage the device has.
• iOS may pause work when an app goes to the background, so keep the screen on during large extractions.

Troubleshooting

The password is rejected

Check case and keyboard language. With a 7z that also encrypts filenames, even the file list appears only after the password is accepted.

Filenames are still garbled

Try another encoding in filename repair.

A split set will not open

Make sure all parts are in the same place and none was renamed.

The file is .egg

That format is unsupported. Ask the sender for ZIP or 7z.

Limits and known issues

• RAR can be extracted but not created. Creating RAR is not possible for third-party apps under the license. LZH is extract-only too.
• EGG files are not supported. The reason is licensing and patent concerns; ask the sender to resend as ZIP or 7z.
• Split archives need every part. A single missing part prevents extraction, and there is no feature to create split archives.
• Encoding detection can be wrong. The development notes record that very short Japanese names can be misread as Korean. If the result looks odd, change the encoding yourself.
• iOS cannot keep extracting in the background. By the OS model, work can stop when the app goes to the background, so the app is designed to keep the screen on while extracting, and solid archives (many files compressed as one stream) cannot be resumed midway.
• Same-Wi-Fi transfer is not encrypted. Use it only on a network you trust.
• Free allows 3 compressions and 3 extractions per day. Browsing, searching, previewing and filename repair do not count toward it. Removing the limit needs a subscription.
• Support for creating some formats varies by version. For example, creating tar-family archives is a recent addition, so check the store's version history.

How it compares

If you only open a ZIP or two, the built-in tools are enough. When Korean names garble, when you receive RAR or 7z, or when you have to open a multi-gigabyte set, a dedicated app saves time.

Sources and further reading

1. PKWARE: ZIP File Format Specification (APPNOTE 6.3.9), general purpose flag bit 11 and filename encoding
2. Microsoft Learn: Code page identifiers (CP949 and others)
3. 7-Zip: the 7z format

FAQ