How to batch convert images online
Converting photos one by one is a waste of your afternoon. Here's how to convert 100+ images at once, straight from your browser.
Why batch conversion matters
Phone photo libraries accumulate fast, five thousand photos in a couple of years is entirely normal. When you need them as JPG for a project, an upload, or a move to another system, doing it one at a time is not a real option.
The arithmetic is brutal. At fifteen seconds per photo, open, export, choose format, name it, save, three hundred photos is well over an hour of clicking, and it is an hour where a single mis-click loses your place.
Batch conversion turns that into one selection, one button, and one download. This converter handles up to 200 files per run, in your browser, with no upload step.
The workflow
Select your files, or drag a whole folder onto the page. Choose the output format. Hit Convert, then download everything as a single ZIP. On a typical laptop, 200 photos finish in well under a minute.
Files are processed one after another rather than all at once, so progress moves steadily and memory stays under control even on a modest machine. Original filenames are preserved. IMG_4821.HEIC comes back as IMG_4821.jpg, so a large batch stays in an order you recognise instead of arriving as image_1 through image_200.
Nothing is modified in place. Your originals stay exactly where they were, and the converted copies arrive as new files, so a run is never destructive and you can redo it if you want different settings.
Choosing the output format
JPG is the right answer most of the time. It is what you want for email, uploads, printing services, and anyone whose software you cannot predict. Quality 92% is visually indistinguishable from the original for ordinary photographs.
PNG is lossless and supports transparency, which makes it correct for screenshots, logos, line art, and anything with hard edges or flat colour. It is the wrong choice for photographs, where it produces files several times larger than JPG for no visible gain.
WebP is roughly 25-35% smaller than JPG at similar quality and every current browser reads it. Use it when the destination is a website you control.
AVIF compresses harder still and is the best choice for web publishing where you know the audience has modern browsers. It is not a good choice for sending to other people.
PDF is worth remembering when the destination expects a document rather than an image, printers, forms, and submission portals often do.
Why the limit is 200
The cap is honest engineering rather than an upsell. Decoding an image expands it enormously: a 12-megapixel photo is around 3 MB on disk but roughly 48 MB once decoded to raw pixels in memory. Browsers hold a finite amount, and a tab that asks for too much is killed by the browser rather than slowed down.
Converting sequentially keeps only a small number of images in memory at once, which is what makes 200 safe on an ordinary laptop and on a phone. There is no daily limit, so a library of two thousand photos is ten runs, not a paywall.
If you are working through something that large, keep each batch's ZIP separate rather than merging as you go. A missing batch is obvious; a missing file among thousands is not.
Mixed batches and files that fail
A batch does not have to be all one format. HEIC, PNG, WebP, AVIF, BMP and GIF can go in together and come out as whatever single format you chose.
If a few files fail, genuinely corrupt, truncated by a bad transfer, or not actually images despite the extension, those are skipped and the rest still convert. You do not lose the run to one bad file, and the ZIP tells you what you got back.
The most common cause of an unexpected failure is a file that was interrupted mid-copy from a phone or camera card. Re-copying that file usually fixes it.
The privacy problem with most batch converters
This matters more with batches than with single files, and it is worth being blunt about. Most online converters upload your images to a server, convert them there, and send them back. That means a copy of every photo in the batch leaves your device and lands on hardware you do not control, governed by a retention policy you have probably not read.
For a screenshot of a spreadsheet that may be fine. For a few hundred personal photos, family, documents, anything with faces or addresses in it, it is a meaningful decision, and most tools do not make it clear that it is being made.
A converter that runs in your browser removes the question entirely, because there is no upload step to have a policy about. You can verify that claim yourself rather than take it on trust: load the page, disconnect from the internet, and convert anyway. It still works, because everything needed is already in the tab.
Quick questions
What's the maximum batch size?
200 files per batch. No daily limit, run as many batches as you need.
Will batch conversion reduce quality?
Only if you set quality below 90%. The default 92% is visually lossless for most images, and resolution is never reduced.
Can I get all files in one download?
Yes, every batch produces a single ZIP containing all converted files.
Can I mix formats in one batch?
Yes. HEIC, PNG, WebP, AVIF, BMP and GIF can be converted together into one output format.
What happens if one file is corrupt?
It is skipped and the rest of the batch still converts. One bad file never costs you the whole run.
Do the converted files keep their names?
Yes. Original filenames are preserved, so a large batch stays in a recognisable order.
Why only 200 at a time?
Decoded images take far more memory than their file size, around 48 MB for a 12-megapixel photo. The cap keeps the browser tab stable rather than letting it be killed mid-run.
Are my photos uploaded for batch conversion?
No. Everything happens in your browser. Load the page, disconnect from the internet, and conversion still works.
Converters
The converter on this page handles every conversion this guide talks about.