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Need help?PNG to PNG: What This Page Is For
A PNG going in and a PNG coming out is not a copy — the image is decoded and written again on our servers, which is exactly why the page is useful. It is how you cut a screenshot down to a size limit, force an exact pixel width, cap a logo to a small palette, or rewrite a file that some upload form refuses. The one thing to know before you start: only the "Highest" preset writes a full-colour PNG. Every other preset, including the one that is preselected, runs a palette quantiser first, which is a lossy step that typically saves four-fifths of the file.
How to Convert PNG to PNG
- Upload Your PNG File: Drag and drop onto the page or click "+ Add Files".
.pngand.apngare both accepted, and a queue of files all share the same settings. - Pick a Quality Preset or a Specific File Size: Under "Image Compression", "Quality Preset" opens on "Very High (Recommended)" and runs from Highest to Lowest; only "Highest" skips the palette pass. Choose "Specific file size" instead to name a target in B, KB or MB and let the converter search for settings that fit.
- Set Colors, Compression Level and Compression Speed: "Colors" offers ORIGINAL, which applies no reduction of its own, or "By Color Reduction + Dither", which exposes a palette size from 256 down to 2 plus a Dither toggle. "Compression level" (1-10) trades encoding time for file size, and "Compression speed" (1-10) does the same for the palette search.
- Choose the Image Resolution and Convert: "Keep original" is preselected; "Resolution Percentage", "Preset Resolutions" (a target height, width follows your aspect ratio), "Width (Keep aspect ratio)", "Height (Keep aspect ratio)" and "Width x Height" all take explicit values. Click "Convert" and download. No sign-up, no watermark.
The Default Preset Is a Palette Quantisation
PNG's own compression is lossless — but a 256-colour palette PNG is still a PNG, and that is what every preset below "Highest" produces. The quantiser picks the best palette it can for your image, so photographs come back looking close to the original at a fraction of the size, while smooth gradients can show banding.
Measured on a 1600 x 1000 photographic PNG of 8,240,545 bytes:
| Setting | What runs | Output size | Colours kept |
|---|---|---|---|
| Highest preset | Full-colour re-encode only | 4,087,065 B | 942,963 |
| Very High (preselected) and below | Full-colour re-encode, then palette quantisation | 835,720 B | 256 |
So the preselected setting is roughly five times smaller than the lossless one on that file. That is the right default for the web and the wrong default for a master copy — if this PNG is your archival original, pick "Highest" before you convert.
Compression Level and Speed, Measured
"Compression level" is the deflate effort the encoder spends. It matters enormously on flat graphics and hardly at all on photographs, because noisy pixel data does not compress whatever effort you throw at it:
| Compression level | 1200 x 800 flat graphic | 1600 x 1000 photograph |
|---|---|---|
| 1 | 28,276 B | 4,118,410 B |
| 3 | 27,938 B | 4,114,771 B |
| 6 | 11,306 B | 4,087,065 B |
| 9 | 11,002 B | 4,087,065 B |
| 10 | 11,306 B — identical to level 6 | — |
Two things worth knowing from that table. First, level 9 is the real maximum: the dropdown offers a 10, but the PNG encoder's range stops at 9, so a 10 falls back to the encoder's own default and lands on exactly the level-6 byte count. Second, on photographs the whole control is worth under 1% — reach for the palette settings or the resolution instead.
"Compression speed" tunes the palette search rather than deflate. On the same photograph, speed 1 produced 834,370 B, the preselected speed 4 produced 835,720 B, and speed 10 produced 906,380 B — about 8% larger for the fastest setting. Leave it low unless you are pushing a big batch through and want the queue to finish sooner.
Transparency, Colours and Animated PNG Input
- Transparency survives. We converted a PNG whose only content was a 60%-opaque circle on a transparent background; the output kept a full alpha channel with the same partial transparency. Nothing on this page flattens alpha onto a background colour.
- The "Colors" control is a hard cap, not a target. Setting 16 colours on a photograph will produce a 16-colour image, posterised and obvious. It earns its keep on flat art — icons, diagrams, logos, screenshots of text — where a small palette costs nothing visible and shrinks the file dramatically. Turn "Dither" on when a reduced palette shows banding across a gradient, and off when you want crisp flat areas to stay flat.
- An
.apngupload comes back as a single still. The decoder reads frame one and writes an ordinary PNG with no animation control block, so the other frames are gone. That is correct for a PNG target — PNG has no animation — but it is rarely what you wanted. To keep the animation, use compress APNG instead, which stays inside the animated format.
If your only goal is a smaller file and you would rather not pick between the levers, compress PNG is the page for that, and PNG to JPG is the bigger saving still on photographs — at the cost of transparency, which JPEG cannot store.
Frequently Asked Questions
Is PNG to PNG lossless?
Only at the "Highest" preset. PNG's compression is mathematically lossless, but every preset below Highest sends the image through a palette quantiser first, which throws colours away before the lossless encoder ever runs. On the file we measured, the preselected preset reduced 942,963 distinct colours to 256 and cut the file from 4.09 MB to 0.84 MB. Choose "Highest" for a pixel-exact result, and anything below it when size matters more than colour fidelity.
Why would anyone convert a PNG to a PNG at all?
To change something other than the format: to get under a size limit, to force an exact pixel width or height, to cap the palette for a small icon, or to normalise a folder of mixed exports to one consistent setting. It is also a practical fix for a file that a strict uploader rejects for an unusual bit depth, colour type or metadata block — a clean re-encode produces a plain, ordinary PNG that almost anything will accept.
Will my transparent background stay transparent?
Yes. Alpha is carried through both the re-encode and the palette pass — we measured a partially transparent test image and the output kept its alpha channel with the same partial opacity. Transparency is only lost if you convert to a format that cannot store it, such as JPG, where transparent areas are filled with a solid colour instead.
What is the highest compression level I should use?
Nine. The dropdown lists a 10, but the PNG encoder's compression range ends at 9, so selecting 10 silently falls back to the default effort — we measured it producing byte-for-byte the same size as level 6. On flat graphics the jump from level 1 to level 9 was 28,276 B down to 11,002 B, so it is well worth setting. On photographs the same change saved under 1%, and the palette or resolution controls are the ones that matter.
Can I upload an animated PNG and get an animated PNG back?
Not from this page. An .apng is accepted, but only its first frame is decoded and the output is a plain static PNG with no animation block — we verified this on a three-frame APNG, and the output contained just the opening frame. If you want to keep the animation while making the file smaller, use compress APNG, which stays within the animated format instead of flattening to a still.
How do I get a PNG under a specific file size?
Switch "Image Compression" to "Specific file size", type the limit with its unit, and let the converter search. It re-encodes repeatedly, tightening the settings until the result lands under your number, and the "Auto Scale" toggle lets it reduce the pixel dimensions too when the palette alone cannot get there. For a large screenshot heading into an email or a forum, Auto Scale is usually what makes an aggressive target achievable.
Why does my gradient look banded after conversion?
Because a 256-colour palette cannot represent a smooth gradient. The quantiser distributes those 256 entries across the whole image, so a long sweep from one colour to another turns into visible steps. Two fixes: switch "Colors" to "By Color Reduction + Dither" and turn Dither on, which scatters the error and hides most banding at the cost of a slightly larger file, or use the "Highest" preset to skip quantisation entirely.
Does this remove the metadata in my PNG?
The re-encode is not a metadata-scrubbing tool, and you should not rely on it as one. If your PNG carries text chunks, an embedded colour profile or software tags that you specifically need removed — or specifically need kept — check the output rather than assuming. Nothing on this page exposes a metadata switch, and the palette pass rewrites the image data regardless of what the ancillary chunks say.
How are my files handled, and how long do you keep them?
Your PNG is uploaded over an encrypted connection, decoded and re-encoded on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public. The practical limit on a big batch is upload time rather than anything in the encoder; a folder of full-resolution screenshots is a lot of megabytes before any work begins.