Reset to defaults
Need help?JPG to JPG: Why a Same-Format Conversion Exists
Converting a .jpg to a .jpg sounds like a no-op, and it would be if the file were copied. It is not. Every file you send here is decoded to pixels and encoded again on our servers, so the output is a new JPEG written at the quality, size and dimensions you choose. That is what makes the page useful: it is how you shrink an oversized photo to a size limit, force a strict pixel width, normalise a folder of mixed-quality images to one setting, or rewrite a file that a fussy uploader rejects. It is also why the wrong setting can make the file bigger — the default preset writes at a higher quality than most cameras and phones use.
How to Convert JPG to JPG
- Upload Your JPG File: Drag and drop onto the page or click "+ Add Files".
.jpg,.jpegand.jfiffiles are all accepted, and you can queue a batch — every file in the queue is processed with the same settings. - Choose a Quality Preset or a Specific File Size: Under "Image Compression", "Quality Preset" runs from Highest down to Lowest, with "Very High (Recommended)" preselected. Switch to "Specific file size" instead if you have a hard limit to hit, and type the number with a B / KB / MB unit.
- Set the Image Resolution: "Keep original" is preselected. "Resolution Percentage" scales by a percentage, "Preset Resolutions" sets a target height with the width following your photo's aspect ratio, and "Width (Keep aspect ratio)", "Height (Keep aspect ratio)" and "Width x Height" take explicit numbers in pixels or percent.
- Pick the File Extension and Convert: The "File extension" group decides whether the download is named
.jpgor.jpeg— the bytes are identical either way. Click "Convert" and download. No sign-up, no watermark.
What Each Quality Preset Actually Writes
Each preset maps to a fixed JPEG quality value, and the encoder changes chroma handling at 90: at Q90 and above it keeps full-resolution colour (4:4:4), below that it halves colour resolution in both directions (4:2:0). That threshold is the single biggest reason a "high quality" re-encode balloons.
The table below is one measured file — a 1600 x 1200 test JPEG of 60,724 bytes, itself written at Q92 with 4:4:4 colour — pushed through the same encoder settings this page uses:
| Preset | JPEG quality | Chroma | Output size | vs. input |
|---|---|---|---|---|
| Highest | 100 | 4:4:4 | 287,355 B | 4.7x larger |
| Very High (Recommended) | 95 | 4:4:4 | 155,309 B | 2.6x larger |
| High | 90 | 4:4:4 | 100,442 B | 1.7x larger |
| Medium | 80 | 4:2:0 | 55,670 B | slightly smaller |
| Low | 70 | 4:2:0 | 48,055 B | 0.79x |
| Very Low | 60 | 4:2:0 | 36,903 B | 0.61x |
| Lowest | 50 | 4:2:0 | 33,951 B | 0.56x |
Your own numbers will differ — a noisy photograph compresses far worse than a smooth test image — but the shape holds: the presets above Medium are quality ceilings, not compressors. If the goal is a smaller file, start at Medium and work down, or use "Specific file size" and let the converter find the quality for you.
Re-encoding Costs a Generation, Every Time
JPEG is lossy on the way in and lossy on the way out, so a re-encode is never a byte-for-byte copy — it is a fresh lossy encode of an already-lossy picture. At Q95 that second generation is close to invisible; at Q50 it stacks visibly on top of whatever the camera already discarded. Three practical consequences:
- Do not re-encode repeatedly. Editing and re-saving the same JPEG five times leaves five generations of artefacts. Go back to the original each time.
- Raising quality cannot restore detail. Converting a Q60 photo at the Highest preset produces a much larger file containing exactly the same damaged pixels.
- Every trip costs the same generation. Converting, then converting the result again to fix the size, spends two generations where one would have done. Decide the final quality and dimensions before you start.
If you only want the file to be smaller and do not care which knob does it, compress JPEG is the page built for that job — it exposes a percentage-of-original target that this converter hides.
Which Control Should You Reach For?
| You want | Use | Notes |
|---|---|---|
| A file under a hard limit (email, forum, form) | Specific file size | Bisects quality to land under your number; enable "Auto Scale" to let it shrink dimensions too |
| A predictable, repeatable quality across a batch | Quality Preset | Same JPEG quality applied to every file regardless of what it started at |
| A fixed pixel size (avatar, banner slot) | Width x Height | Explicit pixels; the other resolution modes keep the aspect ratio |
| The same picture, smaller, minimum fuss | Medium preset | The first preset that reliably reduces a typical camera JPEG |
| A file that opens in a browser instead of Photoshop | Nothing here | Already true of JPEG — you may want JPG to PNG only if you need transparency |
Frequently Asked Questions
Does converting JPG to JPG lose quality?
Yes, a little, always. The file is decoded and re-encoded on our servers rather than copied, so a second lossy generation is written on top of the first. At the default "Very High" preset (JPEG quality 95) the loss is very hard to see, and at "Highest" (quality 100) it is smaller still — but it is never zero, and no JPEG-to-JPEG converter can make it zero. If you need a pixel-exact archival copy, keep the original file, or convert once to PNG at its "Highest" preset, which is the setting that skips palette reduction and stores the pixels exactly.
Why did my JPG get bigger instead of smaller?
Because the default preset writes at JPEG quality 95 with full-resolution colour, which is usually higher than the quality your camera or phone used. In the measured example above, a 60.7 KB source came back at 155.3 KB — 2.6 times larger — purely from the quality jump plus the switch from 4:2:0 to 4:4:4 chroma. Pick "Medium" or lower, or switch to "Specific file size", and the output will shrink.
What is the difference between the JPG and JPEG file extension options?
Only the file name. .jpg and .jpeg are the same JFIF/JPEG format — the three-letter spelling exists because early DOS and Windows filesystems allowed only three-character extensions. The "File extension" group on this page lets you choose which name the download carries so it matches whatever your upload target expects; the bytes inside are identical. .jfif files are accepted as input for the same reason.
Is my EXIF, GPS and camera metadata preserved?
Yes. We measured a round-trip with camera make, model, capture date and GPS coordinates written into the source: all four came back intact in the output file. Nothing on this page strips metadata, so treat that as a privacy consideration too — if you are posting the photo publicly and it carries GPS coordinates, remove them with a metadata tool before sharing.
How does "Specific file size" actually hit my target?
It searches. With "Auto Scale" off, it bisects the JPEG quality value until the encoded file lands under your target and returns the best result it found. With "Auto Scale" on, it first searches for a pixel width that fits and only then tunes quality, which gets a much more aggressive reduction out of large photographs. Very small targets on very large images are the case where you want Auto Scale on — quality alone cannot take a 12-megapixel photo down to 100 KB without turning it to mush.
Can I use this to resize a photo without changing its quality?
You can resize, but not without a re-encode — the resized picture still has to be written as a new JPEG. Set "Width (Keep aspect ratio)", "Height (Keep aspect ratio)" or "Width x Height" for exact numbers, or "Preset Resolutions" to pick a target height with the width following your photo's aspect ratio. To limit the second-generation loss to the minimum, pair the resize with the "Highest" preset — the file will be larger than the source, but the encode adds as little as JPEG can.
Why does the output look softer in the coloured areas at lower presets?
That is chroma subsampling. Below the Medium preset the encoder stores colour at half resolution horizontally and vertically (4:2:0), which is invisible on photographs but clearly visible on saturated edges — red text on white, coloured logos, screenshots of UI. If your image has hard coloured edges, stay at the High preset or above, where colour is stored at full resolution (4:4:4), and control the size with dimensions instead.
Will this fix a corrupt or half-downloaded JPG?
Usually not. A JPEG that is truncated part-way through decodes to a grey or garbled lower half, and re-encoding preserves exactly what the decoder produced — the missing data is not recoverable. What this page can fix is a file that is structurally fine but rejected by a picky uploader: a non-standard colour profile, an unusual chroma layout or a bloated metadata block often becomes acceptable after a clean re-encode.
How are my files handled, and how long do you keep them?
Your JPEG is uploaded over an encrypted connection, re-encoded on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public. There is no per-file count limit on a batch; in practice the upload itself is the slow part, since a queue of full-resolution camera JPEGs is many megabytes before any encoding starts.