Gemini watermark remover supported sizes and formats

The current engine is purpose-built for recognizable visible Gemini image watermarks. It is not a brush-based editor and it does not promise a change for every file. Compatibility depends on two separate questions:

1. Can the runtime decode the file format?
2. Does the pixel data contain a watermark candidate that matches a known or safely localized Gemini pattern?

A valid PNG can still be skipped if its watermark does not validate. A familiar Gemini dimension can also be skipped if the mark has been cropped, resized, recompressed, or otherwise changed.

The fastest way to find out where a specific file lands is to run it through the local browser eraser and read the exact result state. Nothing is uploaded, so an inconclusive answer costs you only the time it takes to select the file.

Supported image file formats

The repository’s current Node adapter explicitly recognizes .png, .jpg, .jpeg, and .webp. Browser decoding depends on the browser, but the public product surface should stay aligned with these tested input families rather than advertising every format a particular browser might happen to decode.

“Supported” should not be read as “guaranteed removal.” It means the adapter recognizes the format and can hand decoded pixels to the detector.

Known Gemini image-size families

Google’s current image-generation documentation describes Gemini image output across 512px/0.5K, 1K, 2K, and 4K tiers, depending on the model. The project’s catalog records exact width and height combinations rather than inferring every case from aspect ratio alone.

The tables below summarize the current catalog in the repository. They are implementation facts, not a promise that Google will never change an output.

Gemini 3.x image catalog

| Aspect ratio | 0.5K | 1K | 2K | 4K | | ------------ | -------: | --------: | --------: | ---------: | | 1:1 | 512×512 | 1024×1024 | 2048×2048 | 4096×4096 | | 1:4 | 256×1024 | 512×2048 | 1024×4096 | 2048×8192 | | 1:8 | 192×1536 | 384×3072 | 768×6144 | 1536×12288 | | 2:3 | 424×632 | 848×1264 | 1696×2528 | 3392×5056 | | 3:2 | 632×424 | 1264×848 | 2528×1696 | 5056×3392 | | 3:4 | 448×600 | 896×1200 | 1792×2400 | 3584×4800 | | 4:1 | 1024×256 | 2048×512 | 4096×1024 | 8192×2048 | | 4:3 | 600×448 | 1200×896 | 2400×1792 | 4800×3584 | | 4:5 | 464×576 | 928×1152 | 1856×2304 | 3712×4608 | | 5:4 | 576×464 | 1152×928 | 2304×1856 | 4608×3712 | | 8:1 | 1536×192 | 3072×384 | 6144×768 | 12288×1536 | | 9:16 | 384×688 | 768×1376 | 1536×2752 | 3072×5504 | | 16:9 | 688×384 | 1376×768 | 2752×1536 | 5504×3072 | | 21:9 | 792×168 | 1584×672 | 3168×1344 | 6336×2688 |

The local catalog also records a 1408×768 16:9 1K variant and a confirmed 2816×1536 variant with a different margin family.

Gemini 2.5 Flash Image catalog

| Aspect ratio | Catalog size | | ------------ | ------------------: | | 1:1 | 1024×1024 | | 2:3 / 3:2 | 832×1248 / 1248×832 | | 3:4 / 4:3 | 864×1184 / 1184×864 | | 4:5 / 5:4 | 896×1152 / 1152×896 | | 9:16 / 16:9 | 768×1344 / 1344×768 | | 21:9 | 1536×672 |

Google’s supported models and dimensions can evolve faster than a local release. The source catalog is therefore a detection prior, not a universal definition of Gemini images.

Known visible watermark geometry

The current source maintains several candidate families because Gemini’s visible logo has changed across output generations:

• 48×48 logo candidates with 32px right and bottom margins for small/current families.
• 96×96 logo candidates with 64px margins for larger and legacy families.
• Evidence-gated large-margin candidates, including 96×96 at 192px right and bottom margins.
• A confirmed 2816×1536 catalog exception associated with the 192px margin family.
• Additional projected and localized candidates for near-official or transformed dimensions.

The catalog candidate is only the start. Validation decides whether a candidate is accepted.

Why a visible watermark can be skipped

The safest detector is allowed to say “no.” Common reasons fall into five groups.

1. The image was resized

Resizing changes the logo size, margins, antialiasing, and alpha edge profile at the same time. Even if the result looks like a normal 16:9 image, it may no longer match the catalog geometry.

Use the original Gemini download when possible. Upscaling a screenshot back to a catalog dimension does not reconstruct the original watermark pixels.

2. The image was cropped or padded

Cropping changes the right and bottom margins. Padding moves the apparent anchor inward. The engine has local search and projected candidates, but it intentionally avoids an unlimited full-image hunt that could mistake content for a watermark.

3. The file was heavily recompressed

JPEG and lossy WebP compression create ringing and block artifacts around high-contrast edges. Because restoration depends on a calibrated alpha profile, enough compression can make the correct inverse model score worse than leaving the pixels alone.

4. The mark belongs to a different family

The visible mark may come from another product, a newer Gemini rollout, a platform screenshot, or an editor overlay. A diamond-like shape is not sufficient evidence. The engine targets measured Gemini profiles, not generic logos.

5. The safety gate rejected the restoration

A candidate position can look plausible but produce worse residuals after inverse compositing. The pipeline evaluates the proposed result and can reject it to avoid damaging genuine image content.

This is not the same as a crash. A reported “no watermark detected” or safety skip can be the correct output for an unsupported or ambiguous file.

Troubleshoot a skipped image

Start with the original file and open the first branch that describes it.

1. 1Is this the original Gemini download? — No, it is a screenshot or social-media copy

   Retrieve the original download. Screenshots and platform exports often change size, crop, compression, and the watermark anchor.

2. 2Is the input PNG, JPEG, or WebP? — No

   The current file adapter does not promise support. Convert only when necessary, preserve the source, and avoid repeated lossy encoding.

3. 3Is the watermark the visible Gemini corner logo? — No or uncertain

   Do not force processing. This is not a generic watermark remover and does not target SynthID, stock marks, signatures, or creator logos.

4. 4Does the full-size original still skip? — Yes

   Keep the unchanged output. The safest next step is evidence-led investigation of the image dimensions, candidate crop, and residuals, not lowering every detection threshold.

What not to do when detection fails

Avoid “fixes” that destroy evidence or increase content damage:

• Do not repeatedly save as JPEG at lower quality.
• Do not resize to a familiar Gemini dimension and assume that restores compatibility.
• Do not blur or paint over the mark before running the detector.
• Do not rename an unsupported file extension to .png.
• Do not treat a skipped result as permission to weaken the safety gates globally.

For a reproducible bug report, keep the untouched source, record its exact pixel dimensions and MIME type, and include a full-resolution bottom-right crop for visual diagnosis. Do not publish sensitive or private imagery just to report an issue.

Output expectations

Even for an accepted candidate, inspect the result at 100% zoom. Fine line art, high-contrast edges, smooth gradients, and compressed textures reveal mismatch faster than a fit-to-screen preview.

The output may retain small residuals when the real alpha edge differs from the calibrated template. Conversely, aggressive cleanup can remove real texture. The project’s production policy favors a narrow, validated restoration over a broad cosmetic edit.

Frequently asked questions

Does the engine support arbitrary resolutions?

It has projected and localized candidate paths beyond exact catalog matches, but arbitrary dimensions are not equivalent to catalog support. Exact known dimensions provide stronger priors; transformed images still have to validate.

Is 4K always easier than 1K?

No. Resolution tier helps choose candidate geometry, but the actual image history, watermark family, compression, and background all affect validation.

Can I convert HEIC to PNG first?

You can create a decodable PNG, but conversion does not guarantee the watermark remains a calibrated match. Preserve the HEIC original and avoid editing or resizing during conversion.

Where to go next

• Test a specific file in the local browser eraser; it processes on your device and reports the decision it made.
• Working from a phone? The iPhone and Android walkthrough covers the picker, the save step, and the mobile video limits.
• Still skipped on an untouched original? Work through the full troubleshooting checklist.
• Judging the result rather than the detection? See removing a Gemini watermark without losing quality.