What the Image Format Converter does
The Image Format Converter switches images between PNG, JPG, and WebP — in any direction. PNG to JPG, WebP to PNG, JPG to WebP, PNG to WebP, JPG to PNG, WebP to JPG. Six conversions in one tool, batch supported, runs entirely in your browser.
It's the universal version of the dozen format-specific converters that clutter most online toolboxes. Convertio has a separate page for every conversion direction; iLoveIMG splits the conversions across half a dozen sub-tools. We collapsed all of it into one widget because the underlying operation is the same — load the image, draw it to a canvas, export the canvas in the target format via canvas.toBlob. The only thing that changes is the encoder.
Nothing uploads. The image never leaves your browser tab. If you watch the Network panel in DevTools while converting, you'll see exactly zero requests for your image data. That's the entire point of building it this way — the alternative is trusting iLoveIMG or Convertio or CloudConvert with your file, which is fine for a vacation photo and less fine for a screenshot of a contract or a corporate dashboard.
How to use it
Four steps.
- Drop or pick your images. Up to 50 MB per image, 200 MB combined. Mix formats freely — you can drop a folder containing PNGs, JPGs, and WebPs in the same operation.
- Pick the target format: PNG, JPG, or WebP. The whole batch converts to whichever one you choose.
- Pick the output quality. Only applies to JPG and WebP (PNG is lossless and ignores the slider). 85% is the default — visually identical to source for almost every photo, with about a third less file size than 100%.
- Click Convert. Each image re-encodes in 1-2 seconds. Filenames mirror the input — vacation.png becomes vacation.webp, screenshot.jpg becomes screenshot.png.
The quality slider locks after the first conversion. That's deliberate: mixing 95% and 60% JPGs in the same batch produces inconsistent results, and we'd rather force a re-start than ship a confusing experience. Clear the queue if you want a different quality.
Picking the right format
Three formats, three different jobs. The picker is the most important decision in the conversion — get it wrong and you either ship a bloated file or lose data you needed.
| Format | Compression | Transparency | Best for | Watch out for |
|---|---|---|---|---|
| PNG | Lossless | Yes (alpha channel) | Screenshots, line art, logos, icons, anywhere you'll re-edit later, anywhere transparency matters | File sizes are big — a photo as PNG is often 5-10× the equivalent JPG |
| JPG | Lossy | No | Photos, photo-sharing with older systems, email attachments, anything where the destination might not support WebP | Transparent areas get painted white. Re-saving repeatedly degrades quality (generation loss) |
| WebP | Lossy (or lossless mode) | Yes (alpha channel) | Web embedding, modern apps, anywhere file size matters and the audience uses modern browsers | Older systems, Microsoft Word, some email clients, and corporate upload forms still reject WebP |
The short version: WebP for the web. JPG for photos shared with strangers or older systems. PNG for screenshots, anything with transparency, and anything you'll re-edit later. The dedicated PNG to WebP, WebP to JPG, and similar tools are search-intent landing pages that all run this same converter underneath.
The lossless rule: if you might re-edit the image later, save it as PNG. JPG and WebP lose quality every time you re-encode them. PNG doesn't. A PNG round-tripped through ten edits looks identical to the original. A JPG round-tripped through ten edits at 85% looks visibly worse than where it started. The math is the math — lossy formats throw away data; lossless ones don't.
Why WebP compresses better than JPG
WebP uses a more efficient compression algorithm derived from the VP8 video codec. At the same visual quality, WebP files are typically 25-35% smaller than equivalent JPG. The technical reason involves intra-frame prediction and block transforms, but the practical reason is simpler — WebP is newer, and the people who designed it learned from twenty-five years of watching JPG run in production.
The catch: WebP is newer. Apple only shipped Safari support in 2020. Microsoft Word still refuses to embed WebP images. Many older email clients can't render them in-line. Corporate web upload forms often whitelist file extensions and forget to add .webp. So WebP is smarter for the web (Chrome, Firefox, Safari, Edge all handle it natively) and worse for everything else.
Worked example: a 1920×1080 photo of a city skyline saved as 100% JPG comes in at around 850 KB. The same photo as 85% JPG is around 380 KB. The same photo as 85% WebP is around 260 KB — about a third smaller than the equivalent JPG at the same visual quality. For a website hosting a hundred such images, that's 36 MB saved per page load, and the difference is invisible to anyone with a modern browser.
A worked example: a folder of mixed PNG and JPG screenshots
Say you have a folder of 40 screenshots from a product demo — some saved as PNG (from the macOS screenshot tool) and some as JPG (saved by a teammate who used Snipping Tool with the JPG default). You want them all consistent for embedding in a blog post.
Open the Image Format Converter, drop the whole folder. The tool reads all 40 files and lists them with their current formats. Pick WebP as the target. Pick 85% quality. Click Convert.
About 60 seconds later, you have 40 WebP files with the original filenames. Combined size dropped from roughly 18 MB (original mix of PNGs and JPGs) to around 6 MB. Every image still looks visually identical at the size they'll appear on the blog post.
The 12 MB of savings translate to faster page loads, better PageSpeed scores, lower CDN costs, and faster delivery on mobile networks. For a single blog post that's a marginal win. For a site with two hundred such posts, it's significant.
If the blog post is going to be embedded in a newsletter that someone opens in Outlook, switch the target back to JPG instead — Outlook still doesn't render WebP in 2026. Same tool, different decision. The Image Format Converter doesn't care which format you pick; it cares that the conversion is fast and the file never leaves your machine.
What happens to transparency
PNG and WebP both support alpha channels — areas of the image can be partly or fully transparent. JPG does not. So converting an image with transparency to JPG produces a question: what should the transparent areas look like in the output?
Our default answer: white. Anywhere the source is transparent gets painted white before JPG encoding. This matches what every other browser-based JPG encoder does. The visual result is what you'd see if you placed the original PNG over a white sheet of paper.
If the transparency matters — you're converting a logo with a transparent background, or an avatar where the rounded corners should stay rounded — convert to PNG or WebP instead, both of which preserve alpha. The tool surfaces this implicitly through the format choice. We don't add an extra "background color" option because every additional option is one more thing for users to get wrong, and the white-or-keep-alpha decision is already encoded in the format pick.
How this compares to the alternatives
| Tool | Where conversion runs | Free-tier cap | Batch | Universal direction |
|---|---|---|---|---|
| Microapp Image Format Converter | Your browser | None (browser memory only) | Yes | Yes — all six directions |
| iLoveIMG | Their server (upload) | 15 files / 100 MB on free tier; paid plan otherwise | Yes | Split across multiple sub-tools |
| Convertio | Their server (upload) | 100 MB total, 10 conversions/day on free tier | Yes | One page per direction |
| CloudConvert | Their server (upload) | 25 conversions/day free; minutes-based paid plan otherwise | Yes | Yes, but behind a complex UI |
| TinyPNG | Their server | 20 images, 5 MB each on free tier | Yes | No — primarily a compressor, conversion is secondary |
| ezgif (jpg-to-png etc.) | Their server (upload) | None on the converter, but ads on every page | Limited | One page per direction |
The pattern repeats. The big commercial converters all do conversion on their servers, all charge for it past some free tier, and all force you through a separate URL for each conversion direction. Microapp does the conversion in your browser using the same canvas API every modern browser ships with, charges nothing because there's no server cost, and presents the whole matrix as one tool because there's no reason not to.
The dedicated converter pages
You'll also see dedicated landing pages for specific conversion directions: WebP to JPG, PNG to WebP, HEIC to JPG, HEIC to PNG. Those exist for search intent — someone Googling "convert webp to jpg" wants to land on a page that says "WebP to JPG Converter" in big letters, not on a generic universal-format-converter page.
Underneath, the conversion logic is the same. The dedicated pages preset the input/output formats and skip the format-picker step; the universal Image Format Converter exposes the full matrix. Use whichever feels more natural for the conversion you're doing right now.
Related Microapp tools
Format conversion is one operation. The full image-workflow toolkit:
- Image Compressor — reduce file size at the same format. Useful when you need a smaller JPG without converting to WebP, or when you need a smaller PNG without going lossy.
- Image Resizer — change pixel dimensions. Useful before conversion if the destination has a size requirement (LinkedIn banner, YouTube thumbnail).
- Image Cropper — trim to a rectangle with optional aspect-ratio lock. Useful before conversion if the destination expects a specific aspect ratio.
- HEIC to JPG — convert iPhone photos to JPG. HEIC is Apple's format and behaves like WebP-from-Google: efficient but unsupported by half the desktop world.
Frequently asked questions
Which format should I pick?
WebP for web embedding and modern apps. JPG for photo-sharing with people whose software you don't control. PNG for screenshots, anything with transparency, anything you'll re-edit later. When in doubt, JPG for photos, PNG for everything else, WebP if you know the destination supports it.
Why does WebP compress so much better than JPG?
WebP uses a more efficient algorithm originally derived from the VP8 video codec. At the same visual quality, WebP files are typically 25-35% smaller than equivalent JPG. The downside is age — Apple only shipped Safari support in 2020, and some older software, email clients, and OS image previewers still don't render WebP. For web embedding, WebP is the smart pick. For sharing with someone whose environment you don't control, JPG is safer.
What happens to transparency when converting to JPG?
JPG can't carry an alpha channel. Anywhere your source image is transparent gets painted white before encoding. If transparency matters, convert to PNG or WebP — both preserve alpha. There's no way to convert a transparent PNG to a transparent JPG; the format doesn't support it.
Is my image really not uploaded?
Correct. Every conversion runs in your browser via canvas.toBlob. Zero outbound requests during the convert. Open DevTools, switch to the Network tab, drop your image, run the conversion, and verify no new requests appear. That's the test.
Can I batch-convert?
Yes. Drop multiple files (or a folder), all get converted to the target format. Each becomes its own download — there's no zip yet. For 5-10 files, sequential downloads work fine. For 50+ files, expect your browser's download manager to queue them up; some browsers will pause and ask permission for the bulk download.
Does the quality slider affect PNG output?
No. PNG is lossless by design — every pixel is encoded exactly as it was. The browser's canvas.toBlob ignores the quality parameter when the target format is image/png. PNG output size depends on image content (areas of flat color compress better; photo-like noise compresses worse) but doesn't change with the quality slider's position.
Why does the quality slider lock after a conversion?
We disable it to keep outputs consistent. Mixing 95% and 60% JPGs in the same batch would produce a folder of files with wildly different quality, and nobody actually wants that. The lock forces a deliberate restart if you want a different quality, which is annoying for the 1% of users who legitimately want a mixed-quality batch and safer for the 99% who don't.
What about AVIF, BMP, GIF, or TIFF?
v1 supports the big three: PNG, JPG, WebP. BMP and GIF can be loaded into the browser, but the tool doesn't expose them as output formats yet. AVIF support is on the roadmap — modern browsers can encode it natively and it compresses even better than WebP. For TIFF and other archival formats, use a desktop tool or round-trip via image-to-pdf then pdf-to-png.