Images are usually the heaviest thing on a web page. Get the format wrong and you ship bloated files that slow every visit, drag down your Core Web Vitals, and cost you in bandwidth. Get it right and the same photo looks identical at a fraction of the size. The catch is that the right answer depends on what the image is — a photograph, a logo, a screenshot, a chart — and on who needs to open it. Let us walk through the four formats that matter today and when to reach for each.
The two things you are trading off
Every image-format decision comes down to balancing three pressures against one another:
- File size and page speed: smaller files load faster, especially on mobile connections, and lighter pages rank and convert better.
- Visual quality: aggressive compression saves bytes but can introduce blockiness, blurring, or color banding if you push it too far.
- Compatibility: a format is only useful if the browser, app, or program on the other end can actually decode it.
Modern formats are impressive precisely because they improve the first two at once — smaller files and better quality. The remaining question is compatibility, and as you will see, that is far less of a concern than it was a few years ago.
JPG: the universal photo format
JPG (also written JPEG) has been the default for photographs since the early 1990s. It uses lossy compression, discarding fine detail your eye is least likely to notice, which makes it excellent for the smooth tones and gradients of real-world photos. Its defining strength is reach: a JPG opens on essentially every device, browser, editor, printer, and kiosk ever built.
The weaknesses are age-related. JPG has no transparency — every pixel is opaque — and it is limited to 8 bits per color channel, so heavy edits can show banding. Compared to newer formats it produces noticeably larger files at the same quality. JPG is a poor choice for sharp-edged graphics, logos, or text, where its block-based compression smears the crisp edges into fuzzy halos.
PNG: lossless graphics and transparency
PNG is lossless: it records every pixel exactly, with zero compression artifacts, and it supports a full alpha channel for clean transparency. That makes it the natural home for logos, icons, screenshots, UI mockups, charts, and any graphic with hard edges, flat color, or text you need to stay razor-sharp. Like JPG, PNG opens everywhere.
The trade-off is weight. Because PNG throws nothing away, a lossless PNG of a photograph is usually much larger than the equivalent JPG — often several times the size. So PNG is the right tool for graphics and anything needing transparency, but the wrong tool for large photos where those bytes translate directly into slower pages.
WEBP: the modern all-rounder
WEBP is Google’s format built specifically for the web, and it is the practical sweet spot for most sites today. It supports both lossy and lossless compression plus transparency, so a single format covers photos and graphics alike. In lossy mode it typically produces files meaningfully smaller than a JPG of comparable quality; in lossless mode it usually beats PNG on size too.
Crucially, compatibility is no longer a barrier. Every current major browser — Chrome, Edge, Firefox, Safari, and their mobile versions — has supported WEBP for years. That combination of small files, transparency, and now-universal browser support is why WEBP is the format most sites should be converting to. If you have a folder of photos, converting JPG to WEBP is one of the easiest page-speed wins available; for graphics and screenshots, PNG to WEBP shrinks them while keeping transparency intact.
AVIF: the best compression available
AVIF is the newest of the four, derived from the AV1 video codec. On compression it is the current leader — at the same visual quality it commonly produces the smallest files of any format here, often clearly smaller than WEBP, while handling transparency and higher color depth with less banding. For photographic images especially, AVIF can look excellent at surprisingly small sizes.
It is supported across all current major browsers, so on the display side it is a legitimate production format. The honest caveats are on the creation side: AVIF encoding is computationally slower than JPG or WEBP, and older or non-browser software — some desktop editors, legacy CMS uploaders, and older operating systems — may still not read it. That means AVIF is a fantastic format to serve, but you will often want a more widely readable fallback for anyone whose tools cannot open it. (For that reason, our converter treats AVIF as an input it can read, not an output it produces — more on that below.)
How to actually choose
Boiled down to practical rules:
- Photographs: reach for WEBP or AVIF for the size savings, and keep a JPG version as a fallback for maximum compatibility. WEBP is the safest default; AVIF wins when you want the absolute smallest files and can afford the slower encode.
- Logos, icons, screenshots, and graphics: use PNG when you need guaranteed lossless fidelity and universal support, or WEBP when you want the same transparency and sharpness at a smaller size.
- Maximum compatibility: stick with JPG for photos and PNG for graphics when a file has to open on unknown, old, or unusual software — email attachments, print vendors, ancient devices.
- Anything with transparency: rule out JPG entirely; choose PNG, WEBP, or AVIF.
Serve more than one format with responsive images
You do not actually have to pick a single winner. HTML’s <picture> element lets you list several sources — say AVIF first, then WEBP, then a JPG or PNG fallback — and each browser downloads the first one it understands. Pair that with the srcset attribute to offer multiple resolutions, so phones fetch small images and large screens fetch big ones. This is the modern best practice: encode once to a few formats and sizes, and let the browser take the smallest file it can display. The result is fast loads for everyone without sacrificing quality or leaving older clients behind.
Where Conversion Wizard fits in
Conversion Wizard is a free, 100% in-browser converter — your files are processed on your own device and never uploaded to a server. It reads a wide range of inputs, including HEIC, JPG, PNG, WEBP, AVIF, GIF, BMP, SVG, and PDF, and outputs clean PNG, JPG, or WEBP. For the web that maps neatly onto the advice above: convert photos to WEBP for a fast, widely-supported modern format, keep JPG when you need the broadest reach, and use PNG for lossless graphics and transparency. If you have older WEBP assets you need to bring back into a universally editable format, you can also convert WEBP to PNG. When you are ready to start, open the converter and drop your files in.
Frequently asked questions
What is the best image format for a website?
For most sites, WEBP is the best default — it is smaller than JPG and PNG, supports transparency, and works in every current major browser. Use AVIF when you want the absolute smallest files and can serve a fallback, PNG for lossless graphics and transparency, and JPG when maximum compatibility matters more than size.
Is AVIF better than WEBP?
On pure compression, yes — AVIF typically produces smaller files at the same quality and handles color gradients with less banding. The trade-offs are that AVIF encodes more slowly and that some older, non-browser software still cannot read it. WEBP has broader tooling support and is easier to produce, which is why it remains the more practical everyday choice for many sites.
Should I still use JPG in 2026?
Yes, in the right places. JPG is no longer the most efficient format, but its universal compatibility makes it the safest choice for photos that need to open on unknown or older software, and it is the ideal fallback in a responsive <picture> setup. Serve WEBP or AVIF first for speed, and let JPG catch anything that cannot read them.
Does converting to WEBP reduce image quality?
Lossy WEBP applies compression, so there is some loss, but at sensible quality settings it is generally invisible while cutting file size significantly. If you need an exact, pixel-perfect copy instead — for a logo or a screenshot — use lossless PNG, which preserves every pixel with no added artifacts.
