How to format converter vs command-line tar / gzip pipelines
- Step 1Decide if metadata matters — If you must preserve Unix mode bits, exact timestamps, or symlinks, the CLI (
tar,cpio) is the right tool. The Format Converter resets mode to 0644 and stamps current time. For content-only handoffs, the converter is fine. - Step 2Decide if you need true 7z / xz output — If the recipient specifically needs a native
.7zor.xz, use7z/xzon the CLI. The converter writes only ZIP, TAR.GZ and GZIP. It can still READ 7z/xz as input. - Step 3Check the environment — On a machine with no shell or no archive binaries, open archive-format-converter in a browser. On a build server with scripting, the CLI integrates better.
- Step 4Drop the archive and pick a target — For the browser path: drag one archive, set
targetFormatto zip / tar.gz / gz, and download. No flags, no temp directory. - Step 5Mind the limits — The CLI is bounded only by disk and RAM. The converter is bounded by tier: Free 50 MB / 500 entries / 1 file. For huge archives, the CLI or a higher tier is the move.
- Step 6Verify the result — After either path, confirm integrity. In-browser, use archive-integrity-tester; on the CLI,
gzip -torunzip -t.
Format Converter vs CLI pipelines
Honest trade-offs. The converter is not trying to replace tar/7z for power users — it covers the no-install, no-upload, content-only cases.
| Dimension | JAD Format Converter | CLI (tar / gzip / 7z) |
|---|---|---|
| Install required | None — runs in browser | Needs tar/gzip; p7zip/unrar for 7z/rar |
| Upload / privacy | No upload, browser-only | Local, but depends on the binary you trust |
| Read coverage | ZIP, GZIP, TAR, TAR.GZ + 7z/rar/bz2/xz/iso (WASM) | Anything, with the right packages installed |
| Write targets | ZIP, TAR.GZ, GZIP only | ZIP, TAR.GZ, GZIP, 7z, xz, bz2, and more |
| Compression level | Fixed level 6 | Fully tunable (-0..-9, -mx=9, etc.) |
| Unix mode / timestamps | Reset (mode 0644, mtime now) | Preserved with the right flags |
| Symlinks / hardlinks | Flattened to regular files | Preserved by tar/cpio |
| Scriptability | Manual, one file at a time | Fully scriptable in CI / cron |
| Max size (Free) | 50 MB / 500 entries | Bounded only by disk/RAM |
| Flag-error risk | None — dropdown | Real (-c vs -x mix-ups) |
Which tool wins, by situation
Pick by constraint, not by habit.
| Situation | Better choice | Why |
|---|---|---|
| Locked-down laptop, no shell | Format Converter | Zero install, runs in any modern browser |
| Confidential archive, untrusted CLI | Format Converter | No upload; nothing leaves the tab |
| Need to extract a vendor .7z to .zip | Format Converter | Reads 7z via WASM without p7zip |
| Reproducible build with exact perms | CLI | Preserves mode bits and timestamps |
| Recipient needs native .7z / .xz | CLI | Converter cannot write those formats |
| 10 GB archive in CI | CLI | No tier size cap; streams to disk |
| Batch convert 200 archives nightly | CLI | Scriptable; converter is one file per run |
Cookbook
Equivalent operations shown both ways — the CLI command and the converter's dropdown choice — so you can pick per task.
ZIP → TAR.GZ
The everyday Linux-ward conversion.
CLI: unzip app.zip -d tmp && tar -czf app.tar.gz -C tmp . Format Converter: drop app.zip → targetFormat: tar.gz → download app.tar.gz Difference: CLI keeps perms/timestamps; converter resets them.
TAR.GZ → ZIP
For a Windows recipient or a web upload form.
CLI: mkdir tmp && tar -xzf build.tar.gz -C tmp && (cd tmp && zip -r ../build.zip .) Format Converter: drop build.tar.gz → targetFormat: zip → download build.zip
7z → ZIP without installing p7zip
The case where the converter clearly wins on a clean machine.
CLI (requires p7zip): 7z x vendor.7z -otmp && (cd tmp && zip -r ../vendor.zip .) Format Converter: drop vendor.7z → targetFormat: zip → download vendor.zip (libarchive WASM reads the 7z; no install needed)
Single file → GZIP
Re-wrapping one payload.
CLI: gzip -k dump.sql # → dump.sql.gz Format Converter: drop dump.sql.zip (single entry) → targetFormat: gz → dump.sql.gz
When the CLI is the only option
Native 7z output — the converter cannot do this.
CLI: 7z a -mx=9 release.7z ./dist/* Format Converter: not possible — it writes ZIP/TAR.GZ/GZIP only. Closest portable output: targetFormat: tar.gz
Edge cases and what actually happens
You expected the converter to keep file permissions
By designUnlike tar, the converter sets entry mode to a default 0644 and ZIP carries no Unix mode field. If permissions matter (deploy scripts, executables), use the CLI with tar or re-apply chmod after extraction.
You expected level-9 compression
Fixed levelThe converter repacks at level 6 with no slider. The CLI lets you set -9 / -mx=9. For browser-side tuning, run compression-level-optimizer on the converted output.
You tried to produce a native .7z
Not supportedNo browser engine writes 7z; the converter writes only ZIP/TAR.GZ/GZIP. The sibling zip-to-7z deliberately produces a TAR.GZ fallback (readable by 7-Zip), not a true 7z. Use the CLI for native 7z.
Archive larger than your tier cap
Over limitThe CLI handles arbitrarily large archives; the converter is capped (Free 50 MB, Pro 500 MB, Pro-media/Developer 2 GB). For very large archives use the CLI or upgrade tiers.
Encrypted input on either side
Rejected hereThe CLI can decrypt with -p. The converter has no password field and libarchive cannot take passwords, so encrypted 7z/rar/zip inputs fail. Decrypt locally first, then convert.
Symlinks must survive
CLI onlytar/cpio preserve symlinks and hardlinks. The converter flattens them to regular files because ZIP has no link concept and the rebuilt TAR writes regular-file headers.
You need to automate hundreds of conversions
CLI winsThe converter is interactive and one-file-per-run. For batch/scheduled conversion, script the CLI. For batch UNPACKING in-browser, see batch-extraction-manager.
WebAssembly disabled in the browser
Partial degradeIf WASM is blocked, 7z/rar/bz2/xz inputs fail in the converter (those need libarchive WASM). ZIP/GZIP/TAR/TAR.GZ still convert via fflate. The CLI is unaffected by browser policy.
Frequently asked questions
Is the Format Converter as capable as command-line tar?
No, and it does not try to be. tar preserves permissions, timestamps and symlinks, and supports any format with the right packages. The converter trades that control for zero install, no upload, and magic-byte format detection — it writes only ZIP/TAR.GZ/GZIP at level 6.
When should I use the browser converter over the CLI?
When you have no shell access, when you want a guarantee that the file is not uploaded, when you need to read a 7z/rar without installing extra tools, or when you just want a quick one-off without remembering tar flags.
When should I use the CLI over the converter?
When you need exact metadata preservation, native 7z/xz output, level-9 compression, archives larger than your tier cap, or scripted batch conversion in CI.
Can the converter read formats the CLI can't?
It can read 7z, rar, bz2, xz and iso out of the box via libarchive WASM, whereas a stock CLI often needs p7zip/unrar installed first. So on a clean machine the converter sometimes has wider read coverage with zero setup.
Does the converter compress as well as `gzip -9`?
Not quite — it uses a fixed level 6, which is the standard speed/size sweet spot. For smaller output, the CLI's -9 wins, or run the converted file through compression-level-optimizer.
Will the converter preserve my Unix permissions like tar does?
No. It sets a default mode of 0644 and ZIP has no standard Unix mode field. If permissions matter, use tar on the CLI or chmod after extraction.
Is my data safer in the browser tool or the CLI?
Both keep data local, but the browser tool removes the question of whether the CLI binary you downloaded phones home — it is just JavaScript and WASM running in your tab with no network calls for the conversion.
Can either tool convert a password-protected archive directly?
The CLI can with -p. The browser converter cannot — it has no password field and libarchive cannot accept passwords. Decrypt locally first.
Does the converter need the internet after the page loads?
Only to load the page and the WASM/JS bundles. The conversion itself runs offline in your tab; nothing about your file is sent anywhere.
Can the converter output a true 7z like `7z a`?
No. It writes only ZIP/TAR.GZ/GZIP. For a portable, well-compressed output choose TAR.GZ; for native 7z use the CLI.
How big an archive can the browser tool handle vs the CLI?
The CLI is limited by disk and RAM only. The converter is capped per tier: 50 MB Free, 500 MB Pro, 2 GB Pro-media and Developer, plus per-archive entry caps (500 / 50,000 / 500,000).
Are there fixed-direction browser tools if I don't want a dropdown?
Yes: zip-to-tar-gz, tar-gz-to-zip and gzip-to-zip each hardcode one direction.
Privacy first
Every JAD Archive tool runs entirely in your browser using fflate, @zip.js/zip.js, and the libarchive WASM bridge. Your archives never leave your device — verified by zero outbound network requests during processing.