Photo tools · Free tool
Image compressor
Tell it the size you need — 100 KB, 500 KB, 1 MB, anything — and it finds the highest quality that fits. Batch up to 40 photos. Your photos never leave your device: no upload, no watermark, no signup.
By Cluzy editors · Verified August 30, 2026
Finds the highest quality that fits under the target. If needed, it also scales dimensions down gently. Files already under the target are left untouched.
What target size should you pick?
Smaller is not automatically better — every kilobyte you remove costs a little quality budget. Match the target to the job:
| Use case | Target | Why |
|---|---|---|
| Marketplace listing photos | 500 KB – 1 MB | Sharp on any screen, fast to upload from your phone |
| Strict web upload forms | 1 MB | The most common form limit; 2 MB is the next most common |
| Emailing a batch of photos | 200 KB each | Keeps 20+ photos under typical attachment limits |
| Avatars and profile pictures | 100 KB | Displayed small — larger files are wasted bytes |
| eBay's hard cap | Under 12 MB | eBay rejects pictures over 12 MB outright |
How target-size compression works
Most “compress to 1 MB” tools apply one fixed quality setting and hope. This one runs a binary search: it encodes your photo at several quality levels, homing in on the highest quality that still fits under your target. If even the minimum acceptable quality is too big — a huge photo forced under a tiny target — it steps the dimensions down 20% at a time and searches again, so you get the largest, cleanest image that honestly fits. Files already under the target are left untouched, and a re-encode that would come out bigger than your original is thrown away in favor of the original. You can watch the per-photo savings appear in the list, with a running total.
Compressing vs. resizing
Compression shrinks the file; resizing shrinks the pixels. If an upload form rejects your photo for its file size, compress it here. If a marketplace wants specific dimensions — 1600 px on the longest side for eBay zoom, a 1200 px square covershot for Poshmark — use our image resizer with its marketplace presets. For most listing photos, resizing to the platform’s recommended dimensions already brings the file size down to a healthy range in the same pass.
Image compression FAQ
How do I compress an image to exactly 1 MB (or 500 KB, or 100 KB)?
Pick "Target file size" mode, choose the size, and hit compress. The tool searches for the highest JPEG or WebP quality that fits under your target; if even minimum quality is too large, it gently reduces the dimensions and searches again. The result is guaranteed at or under the target — not "close to it".
Are my photos uploaded to a server?
No. Compression runs on the encoder built into your own browser. Load the page, go offline, and it still works. Nothing is uploaded, logged, or watermarked, and there are no file limits beyond your device's memory.
Will compressing ruin my photo quality?
At sensible targets, no. A 4 MB phone photo compressed to 500 KB at listing size is visually identical to the original for almost everyone. Artifacts only become noticeable at aggressive targets (say, a large photo forced under 100 KB), and the tool tells you when it had to hit the quality floor.
Why is my PNG so huge in the first place?
PNG is a lossless format — great for screenshots and graphics, terrible for photos. A photo saved as PNG is often 5 to 10 times larger than the same photo as a JPG with no visible difference. The Auto format setting converts PNG photos to JPG, which is usually the single biggest saving available.
JPG or WebP — which should I pick?
JPG is accepted by every marketplace, email client, and upload form, so it is the safe default. WebP is roughly 25 to 35 percent smaller at the same visual quality and every modern browser reads it, but a few older upload forms still reject it. If a site refuses your WebP file, re-run with JPG.
What is the difference between compressing and resizing?
Resizing changes the pixel dimensions (4000 × 3000 becomes 1600 × 1200). Compressing keeps the dimensions but stores the pixels more efficiently at some quality level. Target-size mode here uses both: quality first, dimensions only if needed. If you specifically need marketplace dimensions like 1600 px for eBay or a 1200 px square for Poshmark, use our image resizer instead.
Can I compress a whole batch at once?
Yes — up to 40 photos in one run, with a per-file breakdown of savings and a single ZIP download. The ZIP is assembled in your browser too.
Why did a file come back unchanged?
Two safety rules: a file already under your target size is never touched, and a re-encode that would come out larger than the original is discarded in favor of the original. You will never end up with a bigger file than you started with.
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Free to download · iOS & AndroidSources
Verified August 30, 2026. All compression happens in your browser; your photos are never uploaded or stored.