Compress any image to under 20KB entirely in your browser. Common for signature uploads, small avatars, and certain government portal requirements.
Last updated: August 2026
20KB
Exact Target
All Formats
Input Support
Smart
Two-stage Algo
Private
No Uploads
Drop image here to compress to 20KB
JPEG, PNG, WebP, AVIF, HEIC. All processing stays in your browser.
Want to compare against a looser 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 20KB. Adjust it to any value if your 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 search, then dimension scaling if needed
The tool runs a quality search first, then reduces pixel dimensions in steps if quality alone can't reach 20KB without looking bad. This runs in a background worker, 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.
A 20KB limit is one of the strictest size requirements you will encounter. It is most common for signature images, small avatar fields and specific government portal photographs where storage is extremely limited.
Signature image uploads
Many official forms require a scanned signature as a separate image, often capped at 20KB.
Government portal profile photos
Certain national and regional portals impose a 20KB limit on applicant photographs.
Small avatar and icon fields
Some membership and forum systems restrict profile images to 20KB for storage efficiency.
Exam and application portals
Competitive exam registration systems commonly require a photograph under 20KB alongside a signature under 10KB.
20KB is not a typo. It is one of the strictest image size limits you will encounter outside of embedded systems or fax machines. For context, a typical smartphone photo is 3,000 to 8,000KB. A compressed 100KB portal photo is already 50 to 80 times smaller than the original. Getting to 20KB means compressing to 150 to 400 times smaller than what came off the camera. At that level of reduction, something has to give, and it is useful to know exactly what that something is before you submit.
For portrait photographs, 20KB at the original resolution produces visible JPEG blocking. The kind where smooth skin tones start showing patches and fine detail like hair and fabric texture becomes blurry. This is not a problem with the tool. It is a fundamental limit of what 20KB can hold for a complex, high-detail image. The thing to hold onto is that these portals display the photo at very small sizes, typically 100 to 200 pixels wide. At that display size, the compression is far less visible than it appears when you zoom in on the downloaded file. What looks rough at full size often looks perfectly readable at the size the portal actually renders it.
If the image you need to compress is a signature rather than a photograph, the 20KB limit is much less of a problem. A signature on a white background is exactly the type of image that compresses extremely well: large areas of solid white, simple dark strokes, limited color information. JPEG handles this type of content efficiently even at low quality settings. A clean signature scan at 300 pixels wide will typically reach 20KB with almost no visible quality loss because there simply isn't much information to begin with. The portals that impose 20KB limits for signature uploads understand this. The limit that feels brutal for a photograph is completely reasonable for its intended use case.
For very large or high-resolution source images, the tool cannot always reach 20KB through quality reduction alone. Even at the lowest quality setting that still produces a recognizable image, the output might still be 30 or 40KB for a full-resolution phone photo. When that happens, the tool steps the pixel dimensions down in fixed stages, roughly 75%, 50%, 35%, 25% and then 15% of the original size, re-running the quality search at each smaller size until it finds one that both fits 20KB and clears a minimum acceptable quality. This runs in a background Web Worker, so working through several attempts doesn't freeze the page. A dimensionally smaller image at a reasonable quality is more useful than a full-resolution image crushed to illegibility. If your portal specifies both a file size limit and a minimum pixel dimension, check those requirements before compressing. For portals that need slightly less aggressive compression, the compress to 50KB tool gives you more quality headroom while still meeting the most common strict government portal requirements. Since the tool now recompresses automatically when you change the target, comparing the two takes a single edit rather than starting over.
Expecting a full-color photo to look sharp at 20KB
At this size, a detailed portrait will show visible compression and often smaller dimensions too. A signature or simple scan on a plain background holds up far better, since there's much less detail to encode.
Assuming quality adjustment alone will hit 20KB
For a full-resolution photograph, the tool very often needs to reduce pixel dimensions as well as quality to reach 20KB. That's expected here, check the result panel for the scale factor used if it happens.
Choosing JPEG for a transparent signature scan
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.
Not checking for a separate pixel dimension requirement
Some portals specify both a file size limit and a minimum pixel dimension. Compressing to 20KB satisfies the size requirement but won't guarantee the dimension one, check the portal's stated minimum before submitting.
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, useful for quickly comparing 20KB against 50KB.
Ignoring the warning that the target wasn't fully reached
For an unusually detailed source image, the tool may not be able to hit 20KB at an acceptable quality even after scaling down. When this happens it still delivers its best attempt but flags it on the result panel, worth a second look before submitting.
A 20KB limit is used by systems where storage is extremely constrained or where the image is only displayed at very small sizes, such as a signature field or a small avatar thumbnail. Exam portals and government ID systems are the most common examples.
At 20KB, a typical portrait photograph will show noticeable compression at close inspection but will be fully readable at the small sizes these portals display it. Signature images at 20KB are generally indistinguishable from the original.
Usually a fairly low one for a full photograph. The search can use any quality from 1 to 100, there's no artificial ceiling, but at a target this tight the highest quality that fits is often well below what you'd see on a looser target like 1MB. A simple signature scan is the exception, its lack of detail means it can often hold a much higher quality even at 20KB.
JPEG, PNG, WebP, AVIF, HEIC and HEIF are all supported as input. The output is JPEG or WebP depending on your selection, never PNG. JPEG is the safest choice for submission portals as it is universally accepted.
At 20KB, quality reduction alone is often not enough for a full-resolution photo. The tool first searches for the highest quality that fits within 20KB. If even the lowest quality setting produces a result too degraded to be worth keeping, it steps the pixel dimensions down, roughly 75%, 50%, 35%, 25% and then 15% of the original size, re-running the quality search at each smaller size until it finds one that both fits 20KB and clears a minimum acceptable quality.
This is uncommon but possible for an unusually detailed source image. If none of the dimension steps reach an acceptable quality within 20KB, the tool still delivers the best result it found across every attempt and flags on the result panel that the exact target wasn't fully reached. Try a simpler source image, or a slightly higher target like 50KB, if this happens.
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. This makes it easy to compare 20KB against a looser target like 50KB.
No. The quality search and any dimension-scaling attempts both run in a background Web Worker rather than on the page's main thread, so the tab stays responsive even while working through several attempts to reach a tight target like 20KB.
JPEG has no alpha channel, so a transparent PNG compressed with JPEG selected has its transparent areas filled with a solid color instead. This matters here since scanned signatures are sometimes saved as transparent PNGs. 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.
No. 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. All of this happens entirely in your browser. Your image never leaves your device, you can verify this by disconnecting from the internet after the page loads, the tool still works.
No, this tool handles one image at a time. For a batch of files that all need to fit the same tight limit, run each one through individually.
No sign-up. No uploads. Drop your image above and download the compressed version in seconds.
