First, the thing that explains most problems
Every conversion on this site runs inside your browser. Nothing is uploaded, and there is no server doing the work. That is good for privacy, and it is also why the limits look the way they do: the ceilings exist because your device has to hold the whole image in memory, and a slow conversion means your CPU is busy rather than a queue being long. Closing other tabs genuinely helps, in a way it never would with a server-based tool.
The actual limits
| Tool | Accepts | Produces | Ceiling |
|---|---|---|---|
| Image Converter | JPG / JPEG / JPE / JFIF, PNG, WebP | WebP, JPG, PNG, PDF | 10 MB per image |
| Image Editor | JPG / JPEG, PNG, WebP | JPG, PNG, WebP | 10 MB, 16,384 px per side, 64 megapixels |
| PDF Converter | PNG, JPG | 50 MB per document |
HEIC, RAW formats, TIFF, GIF, BMP, SVG and AVIF are not accepted as input. If a file is rejected and you are sure of the extension, the file’s real format is probably not what its name claims.
Common problems
1The file is rejected the moment I add it
Why: The format is not on the accepted list, or the file is over the size ceiling for that tool.
Check the table above. The image tools take JPG, PNG and WebP only — not HEIC from an iPhone, not RAW files like CR2 or DNG, not TIFF, GIF, BMP or SVG. A file renamed from .heic to .jpg is still HEIC inside and will still be rejected, because the check reads the file’s actual type rather than its name. On an iPhone, setting Camera → Formats → Most Compatible makes new photos JPG.
2A PDF will not open
Why: The document is password-protected or encrypted, or it is over 50 MB.
Encrypted PDFs cannot be decoded in the browser and will fail to load. Remove the password in whatever application created the document, then convert the unprotected copy. If the file is simply large, splitting it into fewer pages per file keeps each one under the ceiling.
3Conversion is slow, stalls, or the tab becomes unresponsive
Why: Everything runs on your own device. There is no server queue — the work is competing for your CPU and memory.
A long PDF or a batch of large photos can take real time, especially on a phone. Close other tabs and applications, convert in smaller batches, and leave the tab in the foreground — browsers throttle background tabs aggressively, which is the usual reason a job seems to freeze halfway. If a single image is enormous, resizing it first in the Image Editor makes the conversion much lighter.
4The download never started, or I cannot find the file
Why: Browsers block or batch multiple automatic downloads, and the destination folder is not always the obvious one.
Look for a blocked-popup or “allow multiple downloads” prompt near the address bar and permit it. Check your browser’s download list rather than the Downloads folder, since some browsers route files elsewhere. On iOS, files usually land in the Files app under Downloads rather than the photo library — converting several images produces a ZIP, which iOS will not expand on its own until you tap it.
5The output looks blurry, blocky, or washed out
Why: The quality setting is too low, or the image was enlarged rather than reduced.
Raise the quality; around 0.8 is the usual sweet spot, and below 0.6 artifacts become visible. Enlarging never adds detail — scaling a 400 px image up to 2000 px just produces a soft 2000 px image. Always start from the largest original you have rather than from a copy that has already been compressed once, since each re-encode compounds the loss. The file size guide shows measured quality-versus-size numbers.
6Transparency turned black or white after converting to JPG
Why: JPG has no alpha channel. Transparent pixels have to become some solid colour.
This is a format limitation, not a bug. Choose PNG or WebP to keep transparency. If you do need JPG, the Image Editor lets you pick the background colour that fills the transparent areas; the Image Converter fills them automatically without asking.
7A converted page from a PDF looks soft when printed
Why: Pages render at 144 DPI, which is a screen resolution rather than a print one.
Commercial printing generally expects 300 DPI. For anything going to a printer, send the original PDF — its text is vector and stays sharp at any size. See the PDF guide for the exact output dimensions per page size.
8The photo came out rotated the wrong way
Why: Phones often store the sensor image as-is plus an orientation flag, and not every tool honours that flag.
The converter reads the orientation flag and bakes the rotation into the pixels, so output should be upright. If a source file has a wrong or missing flag, the rotation controls in the Image Editor will fix it in one step.
9The target file size I asked for was not hit exactly
Why: A target size is approached by trial, not calculated.
The converter repeatedly re-encodes at different quality levels, narrowing in on your target and keeping the closest result under it. How near it lands depends entirely on the image — a noisy photo has a much higher floor than a flat graphic. Treat the target as a ceiling to aim at rather than an exact number.
10It worked on my laptop but fails on my phone
Why: Mobile browsers have far tighter memory limits and reclaim background tabs quickly.
Convert fewer files at once, keep the tab in the foreground for the whole job, and resize large photos before converting. A 48-megapixel photo needs roughly 190 MB of memory just to hold uncompressed while it is processed, which is enough to get a mobile tab killed.
Still stuck?
If none of the above fits, the FAQ covers more ground. When you get in touch, the three things that make a report actionable are your browser and version, the source file’s real format and size, and the exact wording of any message you saw. Please do not attach the file itself — we cannot accept uploads, and describing it is enough.