JPG vs PNG: Which Format Gives You the Smallest File Size?

Choosing between JPG and PNG is not just a technical detail; it can significantly change how fast your website loads and how large your downloads are. Both formats have strengths and weaknesses. This guide explains when each format is best and how to experiment quickly with the Compress It Small image tools.

1. How JPG compression works

JPG is a “lossy” format designed for photographs and complex images. It removes details that the human eye is less sensitive to, which allows very high compression ratios. At moderate quality settings, the loss is usually invisible in normal use.

JPG is ideal for:

• Photos on blogs and portfolios.
• Background images and banners.
• Product photos without transparency.

2. How PNG compression works

PNG is “lossless”, meaning it preserves every pixel exactly. It also supports transparency and very crisp edges, making it perfect for logos, icons and UI elements. However, for complex photos a PNG can be much larger than a JPG of comparable visual quality.

PNG is ideal for:

• Logos and simple illustrations.
• Screenshots with sharp text.
• Graphics that require transparency.

3. Comparing file sizes in practice

To choose between JPG and PNG for a specific image:

1. Upload the original image to the image tools.
2. Export one version as optimised JPG.
3. Export another as optimised PNG.
4. Compare file sizes and visual quality side by side.

In most cases, photos will be far smaller as JPG, while flat graphics with few colours may compress surprisingly well as PNG.

4. What about WebP and newer formats?

Modern formats like WebP can sometimes beat both JPG and PNG in size, but browser and platform support still varies. Compress It Small focuses first on widely supported formats, and you can introduce modern ones gradually once you understand your audience.

If your goal is the smallest possible size, start by choosing the right format for each type of content, then apply additional compression only where it makes sense.

JPG vs PNG in practice: choose based on content, not habit

The “smallest format” question only has a useful answer when you specify the content. JPG is typically smaller for photographs because it uses lossy compression that models how the eye perceives detail. PNG is typically better for simple graphics because it stores sharp edges and flat colors without artifacts.

Choose JPG when:

• the image is a photo (people, landscapes, food, real-world scenes);
• you are publishing on the web and want a small file with acceptable quality;
• you do not need transparency.

Choose PNG when:

• the image has transparency (logos placed on different backgrounds);
• the image is line art (icons, UI screenshots with text);
• you need crisp edges without JPG artifacts.

If you are compressing screenshots, consider resizing first and then testing both formats. Many “huge image” problems are simply over-dimensioned screenshots. Start with Image Tools and compress toward a realistic width for your page.

A simple decision matrix for the smallest possible file

To minimize file size without guessing, apply this decision matrix:

• Photo + no transparency: JPG (resize + moderate quality)
• Logo/icon + transparency: PNG (optimize dimensions; avoid huge canvas)
• Text-heavy screenshot: test PNG first; if PNG is large, try JPG at high quality after resizing
• Need to include multiple images in one upload: compress images first, then combine using JPG to PDF

If your end goal is a document submission rather than an image upload, you may get better results by converting optimized images into PDF using JPG to PDF and then applying PDF Tools to meet portal limits.

Image size has two components: pixels and format

When an image file is “too big,” it is usually because of (1) too many pixels and/or (2) the wrong format. A 4000×3000 photo is excellent for printing, but it is overkill for a website hero image or an email attachment. The same image saved as PNG can be several times larger than JPG because PNG is lossless.

Start by choosing the correct format using the decision logic from JPG vs PNG and then reduce dimensions for your actual use-case. If you need a quick, guided workflow, use Image Tools and keep your output targeted for screens.

A practical workflow for “small but sharp” images

1. Resize first: set a realistic width for the target (blog, portfolio, product listing).
2. Choose the right format: use JPG for photos, PNG for simple graphics that need transparency.
3. Compress gradually: reduce quality in small steps and check at 100% zoom.
4. Strip unnecessary data: metadata is not always huge, but removing it improves privacy and can reduce size.

After optimizing images, you can convert them into a lightweight PDF using JPG to PDF—useful for portfolios, forms, and multi-photo uploads.

Related tools and next reads

Use Image Tools for image compression, and if you need to submit images as a document, convert with JPG to PDF. For deeper workflows, read reduce image size without losing quality and why images are so big (and how to fix them).

Real-world examples: choosing the smallest output

When you optimize an image for the web, you are balancing three things: perceived sharpness, load time, and compatibility. The most common failure mode is compressing aggressively while leaving the image at a huge pixel size. The better approach is to decide the maximum display width first (for example, the width of your content column) and resize to that. Once the image is at the right dimensions, compression becomes far more effective and quality holds up better.

A practical workflow is: resize → choose format → compress → verify. Use Image Tools to do the resizing and compression, then preview the image at 100% zoom. If the image contains text (screenshots, UI), keep quality slightly higher than you would for a photo. If the image is a photo, JPG will often be smaller; if you need transparency or crisp edges, PNG may be better—see the JPG vs PNG breakdown.

If your final goal is an upload to a form or a submission portal, convert optimized images into a PDF using JPG to PDF. That creates a single clean document and lets you do a final size pass with PDF Tools. This is especially useful when a portal accepts one file but you have multiple photos or screenshots to include.

Finally, do not ignore naming and context. Search engines and accessibility tools benefit from descriptive alt text and filenames. Users benefit from images that load instantly. Those small signals add up, especially across many pages and posts.

• Need exact page-size guidance? Use ideal image sizes for blogs and shops.
• Need a step-by-step reduction workflow? Read reduce image size without losing quality.
• Need to understand why images are huge? See why your images are so big.

Optimization checklist for repeatable results

• Need exact page-size guidance? Use ideal image sizes for blogs and shops.
• Need a step-by-step reduction workflow? Read reduce image size without losing quality.
• Need to understand why images are huge? See why your images are so big.

Common mistakes that create multi‑MB images

• Need exact page-size guidance? Use ideal image sizes for blogs and shops.
• Need a step-by-step reduction workflow? Read reduce image size without losing quality.
• Need to understand why images are huge? See why your images are so big.

How to keep images sharp on phones and laptops

• Need exact page-size guidance? Use ideal image sizes for blogs and shops.
• Need a step-by-step reduction workflow? Read reduce image size without losing quality.
• Need to understand why images are huge? See why your images are so big.

Real-world examples: choosing the smallest output

• Need exact page-size guidance? Use ideal image sizes for blogs and shops.
• Need a step-by-step reduction workflow? Read reduce image size without losing quality.
• Need to understand why images are huge? See why your images are so big.