Image compression

Presets vs custom

Picmal ships with six built-in presets that apply sensible quality settings across all image formats. Pick Custom if you want full control over the quality slider for each format.

See compressing files for the presets table.

Lossy formats (Quality 0–100)

These formats use a quality percentage where higher = better quality, larger file.

Format	Range	Default	Notes
JPEG	0–100	85	Most common. 80–90 is usually the sweet spot
WebP	0–100	85	Excellent compression, modern browsers
HEIC	0–100	85	Apple ecosystem, great compression
AVIF	0–100	85	Next-gen, best compression ratios
TIFF	0–100	85	Archival/print use
PDF	0–100	85	Image-in-PDF quality
JP2	0–100	85	JPEG 2000
JXL	0–100	85	JPEG XL
EXR	0–100	85	HDR imagery
PSD	0–100	85	Photoshop files
BMP	0–100	85	Bitmap
TGA	0–100	85	Targa
DDS	0–100	85	DirectDraw Surface
SGI	0–100	85	Silicon Graphics
QOI	0–100	85	Quite OK Image

Level-based formats (1–9)

These formats use a compression level where higher = more compression, smaller file (but processing takes longer).

Format	Range	Default	Notes
PNG	1–9	9	Lossless — level affects compression effort, not quality
GIF	1–9	7	Higher levels mean more aggressive optimization
SVG	1–9	7	Optimization level for SVG cleanup

PDF rasterization DPI

When converting PDFs to JPG or PNG, Picmal rasterizes each page at a chosen DPI. Higher DPI means sharper output and larger files. Pick the resolution in Settings → Images:

DPI	Best For
72	Quick thumbnails, screen previews
150	General web use (default)
300	Print-ready output
600	High-quality print, fine detail

The default is 150, which keeps output crisp without bloating file sizes on multi-page documents.

Quick Guide: What preset should I use?

Use Case	Recommended Preset
Archiving photos, printing	Maximum quality
Portfolio website, client delivery	High quality
Blog posts, documentation	Balanced
Landing pages, e-commerce	Web optimized
Social media posts	Social media
Email attachments, bandwidth-limited	Maximum compression
Specific needs	Custom