What this tool does
Drop up to ten files of any kind and everything that can become a picture comes back as a JPG. The mix does not need sorting first: iPhone HEIC photos, PNG screenshots, scanner TIFFs, AVIF images saved from a website, Windows icons, SVG artwork and PDF pages can all go in together. Anything with no picture inside is listed with the reason rather than failing quietly.
Each result has its own download button, and a single ZIP appears once more than one converted. Everything is decoded and re-encoded in your browser, so the files never leave your device.
Why JPG, when WebP and AVIF are smaller
Because JPG opens everywhere, and that is frequently the only thing that matters. A newer format that a job portal rejects, a print shop cannot place or a colleague's software will not display is worth nothing, however efficient it is. Convert to JPG when the file is leaving your control: upload forms, email attachments, marketplace listings, government portals, older desktop software, anything going to a printer.
Keep the newer formats for pages you publish yourself, where you know the browser can read them. The practical rule is that efficiency is for your own website and compatibility is for everyone else.
What goes in and what comes out
| You drop | You get | Note |
|---|---|---|
| PNG, WebP, BMP, GIF | One JPG per file | GIF gives the first frame, not the animation |
| HEIC / HEIF from an iPhone | One JPG per photo | The usual reason for using this tool at all |
| TIFF from a scanner | One JPG per file | Often a 10x size reduction |
| AVIF | One JPG per file | Usually two to three times larger, which is the price of compatibility |
| ICO | One JPG | The largest image inside the icon |
| SVG | One JPG at the artwork's own size | Transparency becomes white |
| One JPG per page, up to 20 pages | Rendered at 2x | |
| MP4, MOV, WebM and other video | One JPG still frame | The usual way to pull a thumbnail out of a clip |
| Word, Excel, audio, archives | Skipped, with a reason | Nothing inside to render |
Transparency becomes white
JPEG has no alpha channel at all. A transparent PNG logo, an SVG with no background or a screenshot with rounded transparent corners cannot keep that transparency, so transparent pixels are composited onto white before encoding. It is not reversible: once the file is a JPG, the transparency is gone for good.
If the image is a logo, an icon or anything destined to sit on a coloured background, convert it to PNG or WebP instead. Both keep the alpha channel. This is the single most common regret with a JPG conversion, and it only shows up later, once the image is placed somewhere that is not white.
Picking a quality setting
- 0.90 and above — for images that will be edited or printed. The file grows quickly for differences that are hard to see on screen.
- 0.80 to 0.85 — the default choice for photographs. Visually clean at normal viewing size.
- 0.70 to 0.75 — noticeably smaller and perfectly acceptable for anything displayed small.
- Below 0.60 — blocking becomes visible in skies, skin tones and flat areas, and ringing appears around text. Only worth it under a hard size limit.
Before reaching for a lower quality, reduce the pixel dimensions. An image displayed 800 pixels wide gains nothing from being 4000 wide, and halving width and height removes three quarters of the data with no visible cost — far more than compression alone can save.
What a video file gives you
Drop an MP4, MOV, WebM or anything else your browser can play and you get one still frame back, taken a few seconds in rather than at zero — the opening frame of a recording is very often black or a fade, which makes a useless thumbnail. It is the quick way to get a poster image out of a clip without opening a video editor.
It is a still, not a converted video. Turning an MP4 into a WebM, trimming it or changing its resolution is transcoding, and doing that inside a browser means shipping a WebAssembly build of FFmpeg — roughly 25 MB before any video is touched, with the memory use to match. That is a poor trade on a phone, so this tool does the part that is genuinely quick and says plainly that it does not do the rest. A file in a codec no browser ships, which is true of some MKV and AVI files, is skipped with a reason rather than producing a blank frame.
The ten-file limit
The work runs on your own device, in a single browser tab. Ten files a round keeps it quick and stops a phone running out of memory partway through, which would cost the whole batch rather than one file. Larger jobs are simply several rounds — nothing is uploaded, so there is no queue in between. Drop more than ten and the first ten are taken, with a note saying how many were left.