Batch Convert Images on Windows: HEIC, WEBP, AVIF and PDF Without Uploading

You rarely need to "just convert" an image.

What actually happens is this: you have 200 photos from an iPhone in HEIC

format, you need them as JPG, they need to be under 2 MB each for the upload

form, they need to be 1600px wide, and you would rather not publish the GPS

coordinates of your house along with them.

That is four jobs, not one. Most tools do one of them at a time.

This guide covers doing all four in a single pass on Windows, offline, with no

cap on how many files you process.

Why online converters get frustrating

Browser-based converters are convenient right up to the point where they

aren't. The usual walls:

• Batch limits. Twenty files free, more if you subscribe.
• Upload time. A folder of 40 MP photos is several gigabytes going up a

domestic connection.

• One job per pass. Convert, then re-upload to resize, then re-upload to

compress.

• Your files sit on someone else's server. For holiday snaps that may not

matter. For client work, ID documents, medical scans or anything with faces

in it, it should.

Doing it locally removes all four problems at once.

Which output format should you actually pick?

This is where most guides hedge. Here is the short version.

WEBP is the default answer for the web. Google's own

WebP documentation covers the

compression trade-offs in detail, and browser support has been effectively

universal since 2020.

AVIF is genuinely smaller but noticeably slower to encode — on a large batch

that difference is measured in minutes, not seconds. Test it on ten files

before committing to a thousand.

Skip JPEG XL. It is technically excellent and practically stranded:

Google removed JPEG XL support from Chrome

in 2023, and Windows tooling for it remains unreliable. Almost nothing you

publish to will read it.

The HEIC problem

Every iPhone shipped since 2017 defaults to HEIC. It is a good format — better

compression than JPG at the same quality — and Windows support for it is still

patchy enough that people hit a wall constantly.

If you are handed a folder of .heic files and Windows Photos shrugs at them,

you need a converter that reads HEIC natively. Most free desktop tools do not.

Converting HEIC to JPG loses nothing you will notice on screen, and gains you

compatibility with literally everything.

Strip the location data before you post

This is the step people skip.

Every photo your phone takes carries EXIF metadata: camera model, exposure

settings, timestamp, and — if location services were on — the GPS coordinates

where the shutter fired. Upload that photo unmodified and those coordinates go

with it.

Most social platforms strip EXIF on upload. Many forums, messaging apps,

marketplaces and file-sharing services do not. The

EXIF specification

documents exactly how much is stored in there.

You do not have to nuke the whole thing. A good tool offers granular control:

• Remove GPS Only — takes out where the photo was taken, keeps the date,

orientation and camera info. This is what most people want.

• Remove Camera Info — strips make, model and settings, keeps the rest.
• Remove EXIF — clears camera and technical data.
• Remove All Metadata — everything goes.
• Keep Metadata — for archival work where provenance matters.

For selling something on a marketplace with photos taken at home, **Remove GPS

Only** is the setting. It solves the actual problem without destroying the

timestamp you might want later.

Getting the crop right on a batch

Resizing a folder to a fixed square is where automated batches usually go

wrong. Centre-cropping a portrait photo to 1080×1080 will cut somebody's head

off roughly as often as not.

The fix is content-aware cropping. Instead of cutting from the geometric

centre, the tool builds a gradient-energy map of the frame — essentially a

measure of where the detail is — and slides a window across it to find the

busiest region. Faces and text tend to be high-detail areas, so they usually

survive.

"Usually" is the honest word. It finds detail, not faces specifically. On

images that matter, check the preview.

Watermarking without the usual mistake

If you watermark and resize in the wrong order, the mark gets scaled down with

the picture and turns to mush.

The correct order is resize first, watermark second. That way the mark is

rendered at final output resolution and stays crisp.

The second thing that goes wrong: setting a watermark to "40px" looks

reasonable on a 1200px image and vanishes on a 6000px one. Tools that measure

watermark scale against a fixed reference resolution avoid this — one setting

produces a visually identical mark regardless of the source size.

Doing it all in one pass

Here is the workflow that collapses those four jobs into one:

1. Queue the folder. Include subfolders if the images are nested.
2. Set the output format. WEBP for web, JPG for compatibility.
3. Set the resize. 1600px on the long edge is a sensible web default.

Leave the other dimension blank to preserve the aspect ratio.

4. Set the quality. Somewhere around 78–82 is the sweet spot for photos —

visually indistinguishable from the original at normal viewing sizes,

dramatically smaller.

5. Set metadata to Remove GPS Only.
6. Add a watermark if you need one.
7. Pick an output location that is not the source folder.
8. Run it.

A well-built batch tool will keep going if one file fails rather than aborting

the whole run, and will tell you which file failed and why. Losing a 500-file

job to one corrupt image is a bad afternoon.

A note on "AI upscaling"

Be sceptical of this label on free desktop software.

Genuine neural super-resolution — the kind that hallucinates plausible detail

into a low-resolution image — needs a trained model, meaningful GPU time, and

usually a download measured in gigabytes. What is labelled "AI upscale" in most

lightweight tools is high-quality Lanczos resampling with unsharp masking.

That is not a criticism. Lanczos is an excellent resampling algorithm and the

results are clean. But it enlarges what is there; it cannot invent what was

never captured. A blurry 400px photo becomes a larger, smoother, still-blurry

photo. No free portable EXE is going to change that, and any that claims

otherwise is overselling.

Do it with Image Converter Pro

Everything above is how Image Converter Pro

works — a single portable Windows EXE, free, with no installer, no account and

no batch limit.

• Opens 13 formats including HEIC, HEIF, AVIF and JXL
• Saves to 9 including WEBP, AVIF, ICO and multi-page PDF
• Six resize modes including content-aware Smart Crop
• Five metadata modes including Remove GPS Only
• Text and image watermarks, resolution-independent sizing
• Multi-core processing with a configurable worker count
• Nothing is uploaded; the app makes no network requests at all

It is also upfront about what it does not do: the upscaler is Lanczos rather

than a neural model, animated GIFs convert as their first frame only, and

background removal needs an optional package it does not bundle. Those limits

are documented in the app itself, not buried.

Download it, run it, delete it when you are finished. Settings live in

%APPDATA% and nothing else is touched.