What each tool does
Compress makes image files smaller without changing their dimensions or format: a 5MB photo becomes 500KB at the same resolution, via the quality slider. Use it when the problem is file size — uploads, emails, page speed.
Convert changes the format — PNG to JPG, JPG to WebP, any direction — without touching dimensions. Resize changes the dimensions — smaller or larger pixel counts — without necessarily changing format or file size much. Three operations, three distinct problems.
The differences that matter
The key distinction is what changes: compress changes bytes, convert changes format, resize changes pixels. A huge PNG needs resize (fewer pixels) and probably compress (fewer bytes per pixel); a correctly-sized BMP needs convert (better format). Diagnose first, then pick.
They also differ in reversibility: compress and resize discard data permanently (work from originals), while convert between lossless formats preserves everything. Knowing what each operation sacrifices guides the order you apply them.
Which tool for which job
Upload too large? Compress. Wrong format for the platform? Convert. Dimensions wrong for the slot? Resize. Most real jobs name their tool immediately once you phrase the problem as 'what exactly is wrong with this image'.
Common pairings: photos for the web usually need resize then compress; screenshots for sharing need convert (PNG to JPG) plus compress; print files need resize to exact dimensions with minimal compression. Two tools, one workflow.
Using them together
The tools chain naturally in one order: resize first (settle dimensions), then convert (settle format), then compress last (settle bytes). Each step works on the previous step's output, and compressing last means the quality slider judges the final pixels.
Process in batches of up to 20 images per tool run, and keep originals until the final outputs are verified. The chain is fast — automatic processing with instant recalculation — so experimenting with orders costs nothing.
Save the trio as bookmarks in one folder: when an image problem appears, the right tool is two clicks away instead of a fresh search. Small preparation, payoff on every image.
Common confusions
'Compress' vs 'resize' is the classic mix-up: people resize hoping to shrink file size dramatically, or compress hoping to fix dimensions. Remember — resize changes pixel counts, compress changes byte counts; a small-dimensioned uncompressed image can still be enormous.
Another: converting to JPG to 'compress' a PNG. Format change does alter size, but the quality slider on the compressor gives finer control. Convert for compatibility, compress for size — separate goals, separate tools.
Frequently asked questions
What is the difference between compress and resize?
Compress reduces file size (bytes) keeping dimensions; resize changes dimensions (pixels). A huge file needs one or both depending on the actual problem.
Should I convert or compress a PNG?
Convert changes the format (e.g. PNG to JPG); compress reduces size within a format. For photos, JPG + compression usually wins; for graphics with transparency, stay PNG.
In what order should I use the tools?
Resize first, then convert, then compress last — so the quality slider judges the final pixels.