Compress any image to under 300KB directly in your browser. Great balance between quality and size for blogs, CMS, and general web use.
Last updated: August 2026
300KB
Exact Target
JPEG, WebP
Output
Web-Optimized
Quality
Private
No Uploads
Drop image here to compress to 300KB
JPEG, PNG, WebP, AVIF, HEIC. All processing stays in your browser.
Want to compare against a different limit? Change the target field above, no need to drop the file in again.
Five steps is all it takes. Everything runs in your browser so there is no waiting for an upload or server processing.
Set your target
The target is pre-set to 300KB. Adjust it to any value if your CMS or portal has a different limit.
Drop your image
Drag and drop a JPEG, PNG, WebP, AVIF, HEIC or HEIF file onto the tool. No upload happens, the file stays on your device.
Quality check, usually resolved fast
Quality 100 is tried first, and at 300KB it often already fits. Runs in a background worker either way, so the tab stays responsive.
Fine-tune without starting over
Change the target or switch between JPEG and WebP afterward and the tool recompresses automatically.
Download the result
Preview and size stats appear. Download the compressed file immediately.
300KB strikes a balance that most web performance guidelines recommend for inline content images. Below is why it matters.
3x
Faster loading
A 300KB image loads roughly 3 times faster than a 900KB original on an average mobile connection.
90%
Typical reduction
Most phone photos taken at default settings are 2MB to 5MB. Compressing to 300KB achieves 85 to 94 percent reduction.
0
Quality loss visible
At 300KB, most viewers cannot distinguish a compressed image from the original at normal screen viewing distances.
Blog and article images
Inline images in blog posts and news articles should typically be under 300KB to avoid slowing page load and affecting Core Web Vitals scores.
CMS media library uploads
WordPress, Webflow and similar platforms work best with images under 300KB for content sections. Larger images are better suited to hero areas.
Social media open graph
The preview image that appears when a link is shared on WhatsApp, Facebook or Twitter is typically served from a 300KB source.
News and magazine portals
Contributor and journalist photo uploads for editorial content are often capped at 300KB to 350KB by media organisation portals.
Choosing JPEG for a transparent graphic
If the source PNG has a transparent background, JPEG will fill it with a solid color. The tool warns about this and offers a one-click switch to WebP, which keeps transparency.
Using 300KB for a full-width hero banner
300KB works well for inline content images at 800 to 1200 pixels wide, but a full-bleed hero banner on a large screen may show softness at that target. A higher target or the dedicated website-speed tool handles that case better.
Expecting visible quality loss at 300KB
For most phone photos there isn't any. 300KB is generous enough that the fast-path quality-100 check frequently succeeds outright.
Assuming the tool will pad a file up to 300KB
It won't. Compression only ever reduces size. If your image is already under 300KB, the tool detects that and offers the original for download rather than processing it further.
Re-dropping the file just to compare a different target
That's no longer necessary. Changing the target size field after a result already appears recompresses automatically using the same cached image.
Uploading HEIC straight to a CMS that doesn't accept it
Most WordPress and CMS installs reject HEIC silently. Dropping it into this tool first converts and compresses in one pass, outputting a standard JPEG or WebP.
300KB is a common threshold for web content images, CMS upload limits and social sharing previews. Many WordPress, Webflow and Squarespace sites apply a recommended upload size of 300KB for inline blog images and page images to maintain acceptable page load times. It is also a typical limit on news and magazine submission portals for contributor photographs.
Yes. At 300KB, a JPEG image will look crisp and clear at typical web display widths of 800 to 1200 pixels. This is comfortably within the range that Google and other performance tools consider acceptable for blog content images. Larger images such as hero banners and full-width backgrounds may benefit from a higher target to avoid visible artefacts at large screen sizes.
It checks quality 100 first. Because 300KB is a generous budget, a full quality 100 encode often already fits under it for a typical phone photo, in which case that's what you get with no further searching needed. If quality 100 overshoots, the tool binary searches downward to find the highest quality that still fits under 300KB.
Essentially never. 300KB gives the quality search more than enough room for any typical phone photo. Dimension scaling is a fallback reserved for much tighter targets, like 10KB to 30KB, where quality reduction alone genuinely can't reach the target.
You can upload JPEG, PNG, WebP, AVIF, HEIC and HEIF files. HEIC and HEIF are the default formats for iPhone photos and are decoded entirely in the browser without any additional software. The output is either JPEG or WebP depending on your selection, never PNG.
Yes, and it is recommended. WebP is supported by all major browsers and produces smaller files than JPEG at equivalent quality. At a 300KB target, a WebP output will look noticeably sharper than a JPEG of the same size, and it's the only output option here that preserves transparency. Most modern CMS platforms, including WordPress 5.8 and later, accept WebP uploads without any additional configuration.
Yes. The tool keeps the decoded image cached, so adjusting the target size field or clicking JPEG or WebP after a result already appears triggers an automatic recompress rather than asking you to drop the file in again.
No. The quality check and any search that follows both run in a background Web Worker rather than on the page's main thread, so the tab stays responsive even while a large source photo compresses.
JPEG has no alpha channel, so a transparent PNG compressed with JPEG selected has its transparent areas filled with a solid color instead. If the tool detects transparency and JPEG is selected, it shows a warning with a one-click button to switch to WebP, which keeps transparency intact.
No. The image is decoded to raw pixels and re-encoded during compression, so EXIF metadata, including GPS location and camera details, does not carry over to the compressed file.
Yes. Once the page has loaded in your browser, decoding uses the Canvas API, or a dedicated decoder for HEIC and HEIF files, and the compression itself runs via WebAssembly in a background Web Worker. No network connection is required to compress and download your image, and the tool keeps working even if connectivity drops mid-session.
No, this tool handles one image at a time. For a batch of blog images or article photos, run each one through individually.
No sign-up. No uploads. Drop your image above and download the compressed version in seconds.
