Compressing Files

Compress mode reduces file size without changing the format. A JPEG stays a JPEG, just smaller.

How to use

1. Switch to the Compress tab
2. Drop files into the window or click Add Files
3. Pick a preset or configure custom settings
4. Click Compress

Compressed files are saved with a _compressed suffix by default. You can change this to any pattern, including EXIF-based names like {date}_{original}, in Settings → Output. See output and naming.

If the compressed output isn’t smaller than the original, Picmal discards it and leaves the original untouched.

Space saved

When a batch finishes, Picmal totals up how much space you freed and shows it in the bottom bar and the completion notification — with a comparison to put the number in context, like “Freed up 9.66 GB · about a 4K movie 🎬”.

Image presets

Preset	Best For	JPEG Quality	PNG Level
Maximum quality	Archival, print, master copies	92%	2
High quality	Professional websites, portfolios	85%	3
Balanced	General web use, documentation	80%	6
Web optimized	Fast-loading websites	75%	7
Social media	Instagram, X, Facebook	70%	8
Maximum compression	Email attachments, slow networks	60%	9
Custom	Your own settings	You choose	You choose

Audio presets

Preset	Codec	Bitrate	Best For
Maximum quality	FLAC	Lossless	Archival, music production
CD quality	FLAC	16 bit / 44.1 kHz	Lossless CD-equivalent rips
High quality	AAC	256 kbps	Music listening
Balanced	AAC	192 kbps	General use
Podcast	Opus	96 kbps	Speech, podcasts
Voice memo	Opus	64 kbps (mono)	Voice recordings
Maximum compression	Opus	48 kbps	Minimum file size
Custom	You choose	You choose	Your own settings

Video presets

Preset	Codec	CRF	Speed	Best For
Maximum quality	H.265	18	Slow	Archival, mastering
High quality	H.265	20	Slow	High-quality delivery
Balanced	H.265	23	Medium	General use
Web optimized	H.264	23	Medium	Maximum compatibility
Social media	H.264	25	Fast	Social media uploads
Maximum compression	H.265	28	Medium	Minimum file size
Custom	You choose	You choose	You choose	Your own settings

A preset per file

Convert and Compress both have a Preset column. Each row shows the preset that will run on that file — the one from Settings, until you pick another for that row alone. Compress one video hard and leave another balanced in the same batch, without running two passes.

Your saved presets appear in the row menu alongside the built-ins, and the Saving estimate updates as soon as you change one.

To change several rows at once, tick their checkboxes — Compress has the same checkboxes as Convert, plus a Select all videos shortcut — and set the preset from the selection bar. Those ticks also decide which files the next run covers; see run only the files you tick.

A row with its own preset shows a small pin. Pinned rows keep their preset when you change the one in Settings; delete a custom preset and the rows using it fall back to Settings.

A per-file preset changes compression quality only. Resize, color space, and DPI still come from Settings and apply to the whole batch.

Before/after preview

After compressing an image, click the screen icon on any processed file to open a before/after slider. Drag it around to compare the original and compressed versions side by side — useful for dialing in quality when you’re not sure how far you can push it.

Custom settings

Pick Custom to dial in your own quality, codec, bitrate, and other settings per format. See image compression and audio & video for details.

Save your own presets

Once you’ve tuned settings you like, click Save as preset, give it a name, and it appears alongside the built-in presets the next time you compress. Custom presets work for images, audio, and video, so you can keep a “client delivery” or “podcast” preset a click away instead of re-entering values each time.