Image Compressor Limits: 5 Free Tools Measured

An image compressor is capped in three places at once

Comparison articles usually rank these tools by how small the output gets. That is the wrong axis for a free tool, because you will hit a cap long before compression quality matters.

There are three caps, and they are independent. The first two are numbers: how large a single file may be, and how many files go through in one pass. The third is not a number at all — whether the file is uploaded to somebody's server.

The tightest of the three decides your outcome. A tool that accepts unlimited files is no use if each one must be under 5 MB, and a generous size cap is irrelevant if the image is confidential and the tool uploads it.

Every figure in the table comes from the vendor's own page as of September 5, 2026. Free-tier limits move, so check the live page before you plan a large job around one.

Free caps and where each tool runs

Tool	Where it runs	Free cap	Formats
sakuttoAI	In your browser	No service cap	JPEG, PNG, WebP, HEIC
TinyPNG	Server	20 images, 5 MB each	JPEG XL, SVG, AVIF, WebP, JPEG, PNG
Squoosh	In your browser	No service cap	JPEG, PNG, WebP, AVIF
iLoveIMG	Server	200 MB, 30 files per task	JPEG, PNG, GIF
GIMP	On your machine	No service cap	Nearly all formats

TinyPNG stops at 20 images and 5 MB each

TinyPNG's free dropzone states its own limit in the interface: 20 images, with each one capped at 5 MB. That is a per-batch figure. Plenty of comparison articles report it as a daily allowance, which the page does not say.

Two things about it have changed and are worth correcting. The format list now reaches well past PNG, with JPEG XL and SVG sitting alongside AVIF, WebP, JPEG and PNG. The paid tiers raise the per-file cap to 75 MB, or 150 MB at the top, rather than lifting the count alone.

TinyPNG is lossy by design: it cuts how many colors the image uses, so fewer bytes are needed for each pixel. Transparency survives that trade, but the original pixel values do not.

Squoosh keeps the image local but reports its size

Squoosh's repository states plainly that the image is never uploaded and all compression happens locally. For a confidential screenshot or an unreleased design, that one property outweighs every argument about output quality.

The same README is unusually honest about what does get sent. Google Analytics receives the before and after image size value, along with basic visitor data. The pixels stay on your machine; a number describing them does not.

Reading "no upload" as "no data at all" misses that distinction. If your objection to uploading is contractual rather than technical, the difference is worth knowing before you commit.

iLoveIMG allows 200 MB and 30 files in one task

For a large batch, iLoveIMG is the widest free allowance in this set: 200 MB and 30 files in a single task. Paying raises that to 4,000 MB and 120 files.

Read the unit carefully. These are per-task figures, so a second batch starts the count again. That is a different shape of limit from a monthly quota, and a more forgiving one if your work arrives in bursts.

The trade is that the files are uploaded. For holiday photos that is unremarkable. For anything covered by a confidentiality obligation, it moves the decision back to the third cap.

GIMP has no cap because nothing is uploaded

GIMP is desktop software rather than a service, so there is no batch count and no per-file limit to report. Whatever your machine can open, it can export.

What you pay instead is time: exporting one image at a time with a quality slider is slower than dropping thirty files onto a page, and there is no iPhone version. GIMP earns its place when the file is too large for every hosted option, or when uploading is not permitted at all.

Pick the cap that binds you, then pick the tool

Work backward from whichever cap you hit first, not from a ranking of output quality, because the binding cap rules tools out before quality can separate them. Ask about confidentiality first, since that answer removes every server-side tool before any number comes into play.

If the images are confidential, the choice is made before you compare anything else: use a tool that runs in the page. If you need volume and the images are ordinary, iLoveIMG's 30 files per task is the highest free count here. If you are compressing PNG for the web and the files are small, TinyPNG's 5 MB cap will not bother you.

For one enormous file, none of the hosted options apply and GIMP is the answer. Output quality only becomes the deciding factor once two tools both clear your caps, and at that point the gap between them is usually narrower than the gap between formats.

sakuttoAI's image compressor runs in the browser like Squoosh and has no service cap. Drop JPEG, PNG, WebP or HEIC files onto it to compress images and cut their image file size without uploading them to a server.

Summary: choose by the cap your images hit first

The image compressor to use is the one your file size, batch size and confidentiality requirement all fit through, not the one that squeezes hardest. Confidential images point to an in-browser tool, large batches to iLoveIMG, and single enormous files to GIMP.

Check the vendor's page for the current numbers before a large job. Free-tier caps change, and a figure copied into an article does not change with them.