The quality slider
The quality slider controls the trade-off between file size and visual fidelity, typically on a 0–100 scale. Higher values preserve more detail and produce larger files; lower values discard more data for dramatic savings. For most photos, the 70–85 range hits the sweet spot: files shrink enormously with no difference visible at normal viewing distance.
Below about 60, artifacts appear — blocky patches in smooth gradients, smudging around sharp edges, washed-out fine detail. The slider is not a moral choice; it is a budget. Spend quality where eyes will notice it, save bytes where they will not.
Output format: JPG, PNG, or WebP
JPG uses lossy compression tuned for photographs: smooth gradients and natural textures compress beautifully. It cannot handle transparency — transparent areas become a solid color, usually white or black.
PNG is lossless and preserves transparency, making it the right choice for logos, icons, and screenshots with text. The price is larger files. WebP is the modern all-rounder: lossy or lossless, transparency support, and typically 25–35% smaller than JPG at equal visual quality.
Automatic re-processing
Here is the setting you do not have to manage: every change re-processes all images automatically after a short debounce. Move the quality slider and watch every card's sizes and savings update — no apply button, no re-upload.
This turns settings into a live experiment. Drag the slider, compare the numbers, zoom into a card — the cost of trying a different value is zero, so tune fearlessly.
Recommended starting points
Photos for the web: WebP at quality 75–80. Product shots where detail matters: JPG or WebP at 85. Screenshots and graphics with text: PNG, or WebP lossless if every byte counts. Email attachments: JPG at 70 — small enough to send, sharp enough to view.
Treat these as starting points, not rules. Your images, your eyes, your call — the live cards give you the feedback to decide.
Settings for common destinations
Different destinations want different settings. WordPress and most content systems: WebP at 75–80, pre-sized to your theme's maximum display width — the platform will generate its own thumbnails from your upload anyway. Email newsletters: JPG at 70 keeps every image comfortably inside attachment and template size limits.
Social media: JPG or WebP at 70–75, because platforms recompress aggressively no matter what you send — extra quality beyond that is just wasted bytes. Documentation and wikis: PNG for screenshots containing text, where legibility matters more than file size. Match the setting to the destination and you will rarely need to redo a batch.
Frequently asked questions
What quality setting should I use?
For web photos, 75–80 is the sweet spot. Go higher (85+) when detail matters, lower (60–70) for thumbnails or quick sharing where size matters most.
Which format gives the smallest file?
Usually WebP — often 25–35% smaller than JPG at the same visual quality. JPG is the safe universal choice; PNG is for transparency and crisp graphics.
Does changing settings re-compress everything?
Yes, automatically. Adjust the slider or format and all images re-process within a moment — no buttons to press.
Why does PNG not get much smaller?
PNG is lossless: it preserves every pixel exactly, so there is less redundancy to remove. For big savings on photos, switch to JPG or WebP.