How Should You Compress App Store Screenshots?
App store screenshots are almost entirely interface: small text, icons, button borders, plus marketing copy. They tolerate compression far less than photos do — one wrong setting and text edges go soft or pick up colour noise.
Screenshots and photos need different trade-offs
Photo compression aims for "you can't see the difference": smooth gradients like sky or skin can lose a lot of data unnoticed. Screenshots are the opposite — large flat areas and many sharp text edges, and lossy compression damages exactly those edges first. JPEG leaves a halo of noise around letters; PNG palette quantization can band a gradient button.
Screenshots are also what people look at when deciding whether to install, so slightly blurry text costs more than a slightly larger file. The default here is clarity first, size second.
Do not trade pixel size for file size
App stores require specific pixel dimensions, and the wrong size is rejected outright. Keep "Image size" on "Keep original size". tinysqueeze's resize options (longest edge 3840/2560/1920/1280/800px, or scale to 1/2 through 1/10) all change pixel dimensions and do not fit this case.
What each preset does to a screenshot
| Preset | PNG handling | JPEG quality | Good for screenshots? |
|---|---|---|---|
| High quality | No quantization, lossless repack only (oxipng level 2) | 90 | Safest, recommended |
| Balanced | Palette quantization, quality 80 | 75 | Worth trying for flat UI with no gradients |
| Smart auto | Quantization quality searched to a 95% similarity target | Searched by similarity | Worth trying, but check small text in every file |
| Maximum | Quantization quality 55 | 45 | Not recommended — text edges pick up noise |
On High quality, PNG is fully lossless: not a single pixel changes, the data is just stored more tightly. The saving is often modest, but there is no quality risk. If nothing can be saved, the tool hands back the original rather than a larger file.
If a file is still over the limit
- First make sure the screenshot has no wasted content, such as empty margins or duplicated background layers — remove those in the design file.
- Set output format to "Convert all to JPEG" and keep the High quality preset (JPEG quality 90). This helps most with marketing frames that have photo backgrounds or large gradients.
- JPEG has no transparency: transparent areas of a PNG become white when converted. Store screenshots normally should not be transparent anyway, so fill the background in your design tool first.
- Still over? Try Smart auto, then zoom to 100% and check the smallest line of text.
Batch-processing a multi-language set
Put every language and device size in one folder (subfolders are fine) and drag the whole folder in. The whole batch uses one set of settings, so the set stays consistent; then click "Download ZIP".
If a few files need a different preset, there is no need to drop them in again: switch the preset and click "Recompress" on those result cards to redo just them.
- Compare before and after sizes on each card — a PNG that barely shrinks was already tightly stored.
- View every file at 100% and check the smallest text and icon edges.
- Confirm the output dimensions match the originals before uploading.
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