Batch Image Converter

Folders accumulate formats. A few JPGs from a camera, screenshots saved as PNG, images pulled from a website as WebP — and then something downstream wants them all the same. A content system that only accepts JPG, a build pipeline that wants WebP, a client who asked for PNG. This page takes the mixed set and writes every file out in the one format you choose.

The format list is not a menu of promises: JPG and PNG are always there, and WebP and AVIF appear only once this browser has demonstrated it can encode them. Everything runs on your own device.

1. 1Drop up to fifty images. Mixed formats are expected. Each file becomes a row with its original size; duplicates are ignored and anything over the cap is reported.
2. 2Pick the target format. The browser is asked to encode a tiny test image in each candidate format first, so only formats it can genuinely write are listed.
3. 3Set quality, or not. Lossy targets get one quality slider for the whole batch, default 85. PNG and lossless WebP have no quality setting because nothing is discarded.
4. 4Run the queue. Files are converted one at a time so the tab does not run out of memory. Each row shows its finished size, and anything that grew is marked.
5. 5Download. Single files from their rows, or the whole set as a ZIP named after the target format — pixeleditor-webp.zip, pixeleditor-jpg.zip and so on.

Output format

JPG, PNG, and WebP or AVIF where the browser proved it can encode them. WebP is the default because it suits the largest number of jobs.

Quality

One setting for every lossy file in the batch, default 85. 80 to 90 keeps photographs close to their originals.

Lossless WebP

Shown when WebP is the target. Keeps every pixel — right for screenshots and flat graphics, usually much larger for photographs.

Fill colour

Shown when JPG is the target. Transparent areas in PNG, WebP or AVIF sources are blended onto this colour, because JPG has no alpha channel.

Total before / after

Running byte totals across the finished files, so you can see whether the conversion actually saved anything.

Per-file remarks

A row is marked when its output is larger than the original, with both sizes shown.

• Fifty files per batch, because each decoded image occupies width × height × 4 bytes of memory in the tab.
• One format and one quality for the whole batch. Files needing individual treatment belong on the single conversion pages.
• Converting to JPG discards transparency permanently, filling it with the background colour.
• Converting a lossy image to PNG or lossless WebP makes it larger while adding no quality. Those rows are flagged.
• AVIF encodes slowly. A large batch to AVIF can take several minutes, and the option only appears where the browser supports it.
• Metadata is not carried across. Every output is a fresh file with no EXIF, GPS or colour profile.
• Animated GIF and WebP are converted as their first frame only; these are still-image tools.

Say the folder holds twenty JPG photographs averaging 1.2 MB and ten PNG screenshots averaging 900 KB — about 33 MB in total. Converting everything to WebP at quality 85, the photographs typically fall by a quarter to a third, and the screenshots by half or more, bringing the folder to somewhere around 15 MB with transparency intact on anything that had it. The totals shown in the workspace are measured from your actual files.

If the screenshots need to stay pixel-exact, run them separately with PNG to WebP in lossless mode. If the goal is a size limit rather than a format, the batch compressor aims at kilobytes instead.

• Formats verified, not assumed

  WebP and AVIF are offered only after a real test encode in this browser, so a batch never ends in fifty files of the wrong type.

• Mixed input, single output

  No sorting by format first. Drop the folder as it is and everything comes back consistent.

• Honest about growth

  Files that came out larger are counted and marked, rather than being buried in a ZIP for you to discover later.

• No upload, no quota

  Thirty megabytes of assets would be a slow round trip to a server. Here there is no trip at all.

• Names kept sensible

  Each file keeps its name with a new extension, collisions are resolved automatically, and files already in the target format get a “-converted” suffix.

• One ZIP, built in the page

  Packaged in the browser from the finished files, with nothing stored anywhere else.

In this tab, on your device. Every file is decoded and re-encoded here, and the ZIP is assembled here too. No upload request is made, nothing is written to local storage, a cache or a cookie, and the queue is gone when you reload or close the page.

The page sets no cookies and loads no analytics. The host that served it can log the page request itself, as every web host can; the Privacy Policy sets that out and claims nothing beyond it.

PixelEditor is a small set of single-purpose image tools that run inside your web browser. Each one does a specific job — resize, crop, rotate, compress, convert, inspect, strip metadata — and each one has its own page so you can bookmark exactly the tool you keep needing.

The tools are built with the Canvas API and Web Workers. When you pick a file, the browser reads it from your own disk, works on it in memory, and hands you the result back as a download. There is no processing server involved, so there is no upload step, no queue, and no account.

Everything is free, there are no watermarks, and there is no paid tier that unlocks the real version. Read more about how PixelEditor works and why.