Convert images the right way — not just to a different file type

Image tools (convert, resize, compress)

Most tools support batch uploads and instant ZIP downloads. Not sure which format to pick? WebP for web delivery, JPG for universal compatibility, PNG for transparency, AVIF when file size is the top priority and your toolchain supports it.

The one question most people skip before converting

Before you pick a format, answer this: where is this image actually going? Not "what is it" or "what do I have" — where is it going. The destination determines everything: what compression is acceptable, whether transparency matters, what the receiving system can decode, and what file size the upload form will allow.

Most converter sites tell you that WebP is smaller than JPG, that PNG supports transparency, and that AVIF is the future. That's all true. But it doesn't help you make a decision. Here's a more useful frame:

The same 4MB PNG of a product photo might be perfect in your Photoshop workflow, too heavy for a website, rejected by a marketplace upload form, and broken-looking in someone's email. The file hasn't changed — the destination has. That's what format decisions should track.

What actually breaks — and on which platforms

Every format has documented failure modes on specific platforms. These aren't edge cases — they're common enough that they generate thousands of support questions. Here's what actually goes wrong, not in theory but in practice:

• HEIC photos that won't open on Windows 10 / Windows 11

  iPhones have shot in HEIC by default since iOS 11 (2017). Most Windows PCs still can't open HEIC without installing the "HEIC Image Extensions" codec from the Microsoft Store — and many corporate machines can't install it. The result: you send someone a photo and they see an error, or the file shows as unrecognizable. Converting HEIC → JPG before sharing is the only reliable fix that doesn't depend on the recipient's setup.

• Transparent PNG backgrounds becoming black or white on marketplaces

  When you upload a PNG with a transparent background to a product listing — eBay, Amazon, Etsy — the platform's thumbnail generator fills the transparent area with a solid color, often black. Your product photo then appears against a harsh black background instead of white. This isn't a bug; it's what happens when an RGBA image gets composited without a specified background color. The fix: before uploading, either fill the background yourself (white is safest for product photos), or convert PNG → JPG which forces a white fill during conversion.

• WebP images that appear broken in email

  WebP is nearly universal in browsers now, but email clients are different software. Outlook for Windows does not support WebP inline images — recipients see a broken image icon. Apple Mail handles it fine, Gmail webmail handles it fine, but desktop Outlook (still widely used in corporate environments) does not. If you're embedding images in email newsletters or signatures, stick to JPG or PNG.

• Large PNG files hitting upload limits

  A RAW photo exported as PNG can easily reach 20–50MB. Many upload forms — including government portals, job applications, and older CMS systems — cap uploads at 5–10MB. The instinct is to "just compress it," but a PNG is lossless, so compression has a ceiling. The right move is often to convert PNG → JPG (which can cut size by 60–80% for photographic content) rather than trying to compress a PNG further.

• AVIF files that render fine in Chrome but fail in editing tools

  AVIF has broad browser support, but design and editing tools lag behind. Figma added AVIF import support, but Adobe products (Photoshop, Lightroom) have had inconsistent AVIF support across versions. If you're building a web delivery pipeline for photo-heavy pages, AVIF makes sense. If those same files need to pass through a design review in Photoshop or be re-edited, keeping a WebP or JPG master alongside the AVIF is safer than converting your originals.

• JPG artifacts on logos and text

  JPG uses a block-based compression algorithm (DCT) that creates visible "ringing" artifacts around high-contrast edges — logos, text, line art. This is especially visible at boundaries between a white background and dark lettering. If someone sends you a logo as a JPG and it looks slightly fuzzy around the edges, this is why. Always request logos as PNG or SVG; if you only have a JPG, use it at the original size rather than scaling up where the artifacts will enlarge too.

Three things most people get wrong about image formats

Common beliefs about image formats that are either wrong or only half-true:

• Myth: "WebP is always smaller than JPG"

  WebP will often produce a smaller file than JPG at the same visual quality — but not always. For images that are already heavily compressed JPGs (e.g., a photo you downloaded from the web), converting to WebP can sometimes produce a larger file, because WebP is re-encoding an image that has already lost information. The efficiency gains are most pronounced when converting from lossless sources (like PNG or RAW exports) to WebP. If you're converting a JPG from another website to WebP, you may be adding a second round of lossy compression without meaningful size benefit.

• Myth: "PNG gives you the best image quality"

  PNG is lossless, which means it doesn't discard data. But "lossless" and "best quality" aren't the same thing for photographic images. A well-tuned WebP or AVIF file at high quality can look perceptually identical to a PNG at a fraction of the size — because the compression throws away information your eye cannot distinguish anyway. PNG's real advantage isn't quality, it's precision: every pixel is stored exactly as it was. That matters for UI mockups, screenshots with text, and color-accurate design assets. For photos, it just means larger files.

• Myth: "AVIF is ready to replace everything"

  AVIF has excellent browser support and genuinely impressive compression. But "ready for browsers" and "ready for workflows" are different standards. Encoding AVIF is slower than encoding WebP or JPG — on large batches, noticeably so. Toolchain support in design apps, CDNs, and server-side libraries is still catching up. For serving optimized photos on a web page where you control the pipeline, AVIF is a solid choice. For everything else — client deliverables, marketplace uploads, email, cross-team sharing — WebP or JPG will cause fewer problems.

When you should NOT convert your images

This is almost never covered on converter sites, for obvious reasons. But it's genuinely useful: sometimes conversion adds work without adding benefit.

• When the platform re-encodes your image anyway

  Instagram, Facebook, Pinterest, Shopify's CDN, and most social platforms re-encode every image you upload. They don't serve your original file — they serve their own compressed version in whatever format their CDN uses. Uploading a WebP vs. a JPG to Instagram produces the same output image. The platform decides the final format. In these cases, optimizing your upload format is mostly pointless. What matters is starting from a high-quality source so the platform's re-encoding has good input data.

• When you're converting an already-compressed file to another lossy format

  Converting JPG → WebP → JPG is generational loss. Each conversion to a lossy format discards information and introduces compression artifacts. If you need to convert between two lossy formats, do it once, directly, from the best source you have. If you only have a JPG and need a WebP, convert directly. Don't round-trip through PNG "to preserve quality" — PNG doesn't un-compress a JPG.

• When your file is already the right format

  If someone sends you a PNG logo and you need to put it on a white-background website, you don't need to convert it to WebP before use — a properly compressed PNG or an inline SVG will often serve better for that specific case. Conversion for conversion's sake creates unnecessary file management overhead.

Format comparison: what each format is actually built for

Every format was designed to solve a specific problem. Understanding that context makes the tradeoffs obvious:

FAQ — questions that actually come up