Mike Wiberg
Founder, Substrate Apps
Mike has spent twenty years starting and running his own businesses, and Substrate Apps is what that experience taught him to build: software that does one job well, prices it fairly, and treats your files as private by default. He runs the testing behind every platform guide on this site, real files uploaded, real results measured, not repeated hearsay. When something here says a platform compresses your images, it's because we watched it happen.
Questions, or a platform result that does not match yours: support@imagecompressor.tools
How the testing works
Every platform guide on this site starts with two reference files, a 4032x3024 photograph and a transparent PNG. They get uploaded to the real platform through its real interface, downloaded again, and measured: byte counts, pixel dimensions, format, and whether the EXIF block survived. Where the platform serves the file back over the web, the stored bytes are hashed in the browser and compared against the original, so an untouched file can be proven untouched rather than assumed.
Results that came out boring are published as boring. Several platforms leave a file completely untouched, and those pages say so. A guide without a fresh measurement behind it does not ship at all, which is why some platforms are missing rather than estimated.
Recent guides
- Does Bluesky Compress Images? Yes, Twice (Tested)Does Bluesky compress images? Yes, twice. My 4.13 MB test photo came back a 1.56 MB WebP at 4000x3000, 62.3% smaller. Tested 2026-07-18.
- Does Canva Compress Images? Every Export, MeasuredDoes Canva compress images? On export, yes. My 4.13 MB photo came back at 2.34 MB as a JPG and 18.21 MB as a PNG. Dated test, four exports.
- Does Discord Compress Images? Tested Byte by ByteDoes Discord compress images? Barely, my dated test shows: a PNG came back byte identical, a JPEG lost 0.3%. Size caps, mobile settings, real fixes.
- Does Dropbox Compress Images? No, Verified by HashDoes Dropbox compress images? No. Tested 2026-07-18: both files came back sha256 identical. The compressed look comes from previews, not storage.
- Does Facebook Compress Images? Two Files, MeasuredDoes Facebook compress images? Yes, hard: my 4.13 MB photo came back 86.3% smaller at 2048px, and a transparent PNG became a JPEG. Tested 2026-07-18.
- Does Figma Compress Images? I Measured the ExportsDoes Figma compress images? Not on import under 4096px. Exports grew my 4.13 MB photo to 10.78 MB as a JPG and 19.60 MB as a PNG. Dated test.
- Does Gmail Compress Images? Attach vs Inline, MeasuredDoes Gmail compress images? Attached photos arrived byte for byte identical. The same photo inserted inline lost 55.1% of its bytes. Tested 2026-07-18.
- Does Google Drive Compress Images? I Tested It TwiceDoes Google Drive compress images? No. My 4.13 MB photo and 1.78 MB PNG came back byte identical, same sha256 hash. Tested 2026-07-18.
- Does Google Photos Compress Images? Both Modes TestedDoes Google Photos compress images? Storage saver took 35.1% off my 4.13 MB photo. Original quality gave back identical bytes. Dated test, both modes.
- Does Google Slides Compress Images? Yes. I Measured ItDoes Google Slides compress images? Yes: my 4.13 MB photo came back 77.8% smaller at 2048x1536, and a smaller PNG passed untouched. Tested 2026-07-18.
- Does Imgur Compress Images? It Made Mine BiggerDoes Imgur compress images? I uploaded a 4.13 MB photo on 2026-07-18 and got 4.80 MB back, 16.1% larger, EXIF stripped. The PNG shrank 18.8%.
- Does Instagram Compress Images? One Upload, MeasuredDoes Instagram compress images? Yes, but gently in my test: a 4.13 MB iPhone photo came back 5.4% smaller at full size, EXIF gone. Tested 2026-07-18.
Plus 83 more, all written and measured the same way. Browse every guide.