Image Converter & Resizer
The media spec auditor tells you an image is the wrong size or format for a marketplace; this is where you fix it. Pick the platform, drop the files, and get back images that are rechecked against the same rules — not just converted and hoped for.
🔒 Your image data never leaves your browser — decoding, resampling and encoding all run as WebAssembly on your own machine.
Drop product images here
PNG · JPEG · WebP · AVIF (plus GIF/BMP in-browser) · paste works too
Converted, then rechecked — not converted and hoped
Every generic converter can turn a WebP into a JPEG. What it cannot tell you is whether the result will survive the upload: Amazon wants JPEG with the longest side at 1000 px or more before zoom works, Google Shopping and eBay each publish their own floors and formats. The presets here carry those numbers, and after converting, the output is checked against the same rules our media spec auditor applies — the badge on each card is the answer to the only question that matters: is it right now?
This tool refuses to upscale by default
When the platform wants 1000 px and your photo has 800, stretching it adds pixels but no detail — marketplaces detect the blur, and buyers see it. The default here is to keep the original size and say so on the card. Upscaling is a checkbox you tick knowingly, not a thing that happens to you.
What happens to transparency, metadata and animation
JPEG has no alpha channel, so transparent areas are composited onto white — the card says so when it happens. Re-encoding does not carry metadata over: EXIF, colour profiles and GPS coordinates are gone, which for a product photo is usually the point (the EXIF privacy checker shows what was in there). Animated GIFs are refused rather than silently flattened to one frame.
HEIC and TIFF are not supported — here is why, and what to do
HEIC decoding depends on an LGPL library stack over the HEVC codec, which carries patent-pool obligations we are not willing to bury in a "free" tool. Rather than ship it quietly, we say so: convert HEIC on your own machine first — macOS Preview (File → Export), Windows Photos (Save as), or set the iPhone camera to "Most Compatible" so it shoots JPEG in the first place. TIFF is not decodable in most browsers, and print-shop TIFFs are usually CMYK anyway — check those with the colour space checker first.
Every rule this converter applies (5 of its own, plus the platform rules it rechecks)
ICV-001 Animated GIF is not converted
A multi-frame GIF converted to a still format keeps only one frame — the animation is silently lost. This tool refuses instead, and says so.
Fix: Export the frame you want as PNG first, or keep the GIF.
Source: yaktool engineering rule for this converter; not a platform quotation.
ICV-002 Target is larger than the source — not upscaled
Scaling up adds pixels but no detail; marketplaces detect the blur and buyers see it. By default this tool keeps the original size and tells you, instead of stretching.
Fix: Re-export from the original artwork at a larger size, or explicitly enable upscaling if you accept the quality loss.
Source: yaktool engineering rule for this converter; not a platform quotation.
ICV-003 Metadata is not carried over
Decoding and re-encoding drops EXIF, colour-profile and text metadata — including GPS coordinates if the photo had them. For a product image that is almost always what you want.
Source: yaktool engineering rule for this converter; not a platform quotation.
ICV-004 Transparency flattened to white
JPEG has no alpha channel. Transparent areas have been composited onto a white background — the marketplace would have done the same, but on a background of its choosing.
Source: yaktool engineering rule for this converter; not a platform quotation.
ICV-005 Input decoded by the browser, not the shared engine
GIF and BMP inputs are decoded by the browser's native decoder, which the MCP server does not have — the declared cross-entry format set is PNG, JPEG, WebP and AVIF.
Source: yaktool engineering rule for this converter; not a platform quotation.
The recheck badges cite the media spec rules (MED-F01, MED-S01, MED-S02, MED-B01) and the Amazon zoom threshold (IMG-S01) — the same rule IDs, from the same registries, as the media spec auditor and the Amazon main image checker. Sizes come from each platform's published spec, recorded with source and date in the shared registry. Conversion quality is fixed at the same “visually safe” level as the compressor's default; if the file needs to be smaller rather than different, that is the compressor's job.