A lighter batch, with the detail still in view
Bulk Image Compressor
Reduce image file sizes in your browser. Prepare a batch, compare original and exported copies, and see which files meet your chosen KB target.
Your files. Your export budget.
Prepare a lighter image batch
Choose still JPG, PNG or WebP images. Keep their dimensions, or explicitly reduce the longest edge. A missed target stays visible.
Images and export settings
0 keeps original oriented dimensions. Otherwise choose 640–4,096 px. PNG and WebP retain transparency; JPG uses this background.
No images selected
Up to 15 images, 20 MB each and 80 MB total; up to 25 MP and 8,192 px per source side. These are tool caps, not platform limits.
Original and export preview
Select an image to compare
Choose images or load the example to see the source and exported copy side by side.
Your originals stay unchanged.
Images stay in this tab. Keep your source files separately.
Measured results for every image
| Output file | Source | Export | Change | Dimensions | Quality | Target |
|---|
KB means 1,000 bytes. Target mode samples JPG/WebP quality settings from 95 down to 20; PNG uses one lossless canvas encode. No automatic resize forces a target. Exported bytes are not a visual-quality score or platform acceptance check.
How the batch is prepared
Keep the source intact
Each export starts from the selected original. Choose a whole-image size reduction only when you need it; nothing is cropped or enlarged.
Original source → new copyMeasure the real file
Use fixed quality or search sampled quality settings for a byte budget. Files that stay too large are marked instead of hidden.
Measured bytes, explicit target statusReview before the handoff
Compare detail, texture and transparency. Save the images and measured summary together, then inspect the actual destination separately.
Individual image + batch ZIP + reviewDefine what the smaller copy must still do
An image delivery has more than one requirement. A room photograph may need recognizable faces and readable signs. A product cutout may need transparency. A diagram may need fine lines that survive inspection. Write down the role of each asset before choosing settings. Reducing bytes is useful only if the resulting copy still performs that role; an unreadable instruction is not a successful delivery simply because its file is small.
Separate your delivery preference from the requirements of the receiving system. A client might request compact review images for an email attachment, while a designer needs larger references for later work. Those are different copies, not competing judgments about one perfect file. Ask which format, dimensions and file budget apply to the current handoff. Keep the original source available for a later request instead of making a compressed derivative your only working master.
Compression and resizing answer different questions. Encoding changes how image information is stored. Reducing dimensions removes pixel positions from the working image. Either can affect visible detail, and neither guarantees a particular saving. This tool lets you set an optional longest edge separately from the compression mode. It never crops a picture, enlarges a small source, or secretly reduces dimensions because a target-size search failed.
Group assets by their practical needs. A set of photographs can share an exploratory run, while transparent marks or text-heavy graphics may deserve another format and another review. Batch processing saves repeated setup; it does not eliminate individual decisions. If one result needs a different treatment, preserve the useful outputs and run that source again with deliberate settings. Do not lower the standard for every asset just to make a batch look uniform.
Bring supported originals into a local batch
Select up to 15 still JPG, PNG or WebP images, with a maximum of 20 MB per file and 80 MB across the selection. Source images must also stay within 25 megapixels and 8192 pixels on either side. These are this tool’s input bounds, not social posting limits. A compact file can still contain a very large pixel grid, so byte size alone does not determine whether a source is accepted.
Animated images, SVG, GIF, HEIC, video, corrupt files and unsupported content are not accepted. Renaming an extension does not convert an image into a supported format. If you need a still derivative from another source type, prepare it in an appropriate application and keep the source separately. The compressor checks headers before decoding and processes accepted images sequentially rather than decoding the whole batch at once. Processing time still depends on the images and device.
A rejected or cancelled file selection does not replace the previous batch. That protection is useful when a folder contains a mixture of usable assets and unrelated files. Correct the selection and try again; do not assume the earlier work has become the newly selected set. Before encoding, confirm that the visible filenames match the intended delivery. Similar names can hide different revisions even when every file passes the technical checks.
Image processing stays in the browser without sending the source images to a compression server. The originals are not overwritten, and their File objects remain in memory until you clear the batch or close the tab. Keep your source files in your own storage: there is no autosave or resumable project feature. Local processing also does not remove your responsibility to handle downloaded copies and client material carefully on a shared computer.
Choose the format before judging the quality setting
JPG is an option for opaque photographic copies when the recipient wants that format. WebP is another candidate when the receiving workflow accepts it, including images needing transparency. PNG uses a lossless canvas encode and can suit graphics where preserving the rendered edges matters. None is universally smallest. Compare the actual output from the relevant source rather than choosing a format because of a general saving percentage quoted for unrelated pictures.
Fixed-quality mode accepts whole-number settings from 20 to 95, starting at 85. For JPG and WebP, that setting is an encoder request, not a percentage of original detail retained or a measured visual score. Two pictures at 85 can have very different byte sizes and visible weaknesses. Browser encoders can also interpret quality differently. Keep your comparison tied to the outputs you actually produce rather than expecting identical bytes on every device.
PNG ignores the quality control. Moving that control does not instruct a PNG encode to discard more detail, and target mode does not introduce a PNG quality search. A PNG result can therefore be larger than its source or remain over budget. Lossless describes the encoding of the prepared canvas pixels, not a promise that the entire decode, color handling and optional resize path preserves every property of the original file.
Transparency needs an explicit decision. PNG and WebP retain alpha; JPG flattens transparent pixels onto the background you choose, with white as the default. A mark intended for a dark panel may look wrong after a white background is baked in. Inspect partially transparent edges as well as empty corners. If the background is not yet agreed, keep a transparent working copy instead of treating an opaque conversion as an interchangeable replacement.
Understand target-size sampling and optional dimensions
Target mode takes a per-image budget from 10 to 10000 decimal KB, with 200 KB as the default. One KB means 1000 bytes, so a 200 KB budget means 200000 bytes. Each output is checked against that amount independently. An unusually small image does not donate its unused allowance to another image. The ZIP package and reports are separate delivery items; their combined size is not what the per-image target measures.
For JPG and WebP, the tool samples quality settings 95, 90, 85 and so on in five-point steps down to 20. It selects the highest sampled quality whose encoded size is within the budget. It does not test every whole-number setting, establish an optimal visual result, or promise an exact requested byte count. A selected quality of 80 means that candidate met the rule; it is not proof that an untested 83 would fail.
If no sampled candidate fits, the tool keeps the smallest sampled candidate and marks the target missed. That output remains over budget and needs a decision from you. PNG receives one lossless canvas encode, followed by a size check, without a quality search. Neither path reduces dimensions to force a pass. The compressor settings let you make a separate, visible dimension choice when the receiving brief permits one.
Set the optional maximum edge to 0 to retain original oriented dimensions, or choose a value from 640 to 4096 pixels. A 2400 by 1600 image limited to 1200 becomes 1200 by 800; a 600 by 400 source stays that size under the same limit. The aspect ratio is preserved without cropping or upscaling. If the composition itself needs changing, use the image resizer as a separate preparation step.
Follow a print-workshop batch through three outcomes
Consider a fictional community print workshop preparing three stills for an organizer: a room photograph, a close view of ink texture and a simple instruction graphic. The organizer asks for review copies within 250 KB each, not a platform upload guarantee. The operator selects JPG target mode and leaves the maximum edge at 0. The byte sizes below are invented to demonstrate the selection method, not measurements or predictions for your browser.
The room photograph starts at 1120000 bytes. In the illustrative candidate set, every sample above quality 75 exceeds 250000 bytes; quality 75 produces 242000 bytes. The tool chooses 75 as the highest sampled quality that fits. The reduction is 878000 bytes, calculated as 1120000 minus 242000. A reviewer still checks the room sign and the edges of the printing equipment before approving that copy for the organizer.
The ink-texture photograph starts at 860000 bytes, but its smallest sampled candidate is 278000 bytes. That is 28000 bytes above the same budget, so its status is target missed. The instruction graphic starts at 180000 bytes and produces a 196000-byte candidate at quality 95. It fits the target but is 16000 bytes larger than the original. These are different outcomes: the first is smaller and fits, the second misses, and the third fits while growing.
The three outputs total 716000 bytes, compared with 2160000 source bytes. That aggregate reduction does not erase the texture image’s individual miss or establish that the graphic should replace its smaller source. The organizer can accept the room copy, request another treatment for the texture, and retain the graphic source outside the export if appropriate. The compressor does not silently substitute originals to make the saving figures look better.
Compare visible detail as well as byte totals
Select each image and compare the original and output side by side. The contained previews help you inspect the whole composition, while the bounded 100 percent view lets you examine detail without stretching the page around a large image. Check the reported oriented dimensions before interpreting an apparent difference in sharpness. A resized output and an unchanged source do not contain the same number of pixels, even when both previews occupy similar screen space.
Choose inspection areas according to the job. On a face, examine eyes and hair boundaries. On workshop artwork, examine small lettering, thin rules and textured ink. On a product cutout, look for unwanted edge color and an inappropriate flattened background. A small whole-image preview can conceal these changes. Then review at the intended display size too, because a defect obvious under close inspection may or may not affect the actual use.
Read bytes, dimensions, output format, quality setting, size delta and target status together. A green-looking size outcome cannot tell you whether a label remains readable. An enlarged file is not hidden or relabeled as a saving. If you want a percentage reduction, calculate source bytes minus output bytes, divide by source bytes, and multiply by 100. A negative answer means growth; it is not evidence that the tool used the wrong source.
Canvas processing can alter color, profiles and metadata, so keep archival originals and check brand-sensitive colors against the approved reference. Do not use this operation as a certified privacy sanitizer. Compression cannot repair blur, recover missing text or authenticate a photograph. For a separate format preparation review, the social media specs checker addresses another part of the workflow; final acceptance still needs checking in the receiving destination.
Download the deliverables without confusing them with sources
Download the selected encoded image for a focused handoff, or use the ZIP for all encoded outputs with a CSV summary and README. The outputs have unique safe names using a numbered prefix such as 001, a source stem and the output extension. Inspect the mapping when two originals share a name. A reliable delivery identifies which revised file belongs to which source, rather than asking the recipient to infer it from thumbnail appearance.
The ZIP contains encoded outputs, including any you still need to review for target misses or enlargement. It does not replace an unsatisfactory candidate with the original. Keep your own approved delivery set separate if some results should not be used. The original files are excluded from exports. When a client also needs masters, send those separately through your normal approved channel and label them as sources, not compressor-generated results.
Copy the summary or download CSV when another person needs the actual result figures. Use the PDF as a review report containing settings, per-file results, a selected comparison and practical guidance. Its image comparisons are thumbnails, not source files or full-resolution replacements. A report can support a decision about an asset without being the asset itself. Confirm that the recipient has the encoded image files when they need usable media.
Changing settings, cancelling work or clearing the batch invalidates pending results and exports. Finish the current run and check its visible settings before preparing the final handoff. Downloaded files from earlier runs remain separate files on your computer, so keep revisions organized yourself. None of the reports recreates an editable session. If the brief changes tomorrow, return to the stored originals and make a new set of derivatives instead of recompressing yesterday’s delivery.
Connect preparation to the next real task
The destination selector covers Instagram, TikTok, YouTube, Facebook, LinkedIn, Threads, X, Snapchat and Reddit as intended-use labels. It does not apply hidden platform dimensions, inspect an account, or certify upload compatibility. Keep the chosen context with your review notes when it helps a colleague understand the asset. Then check the actual destination and placement independently, especially when the same image will be used in more than one setting.
Use another preparation tool only when it resolves a remaining task. The carousel maker can help assemble a sequence after the individual assets are ready. The thumbnail and title preview supports a separate composition review. Neither step turns a compression result into a native platform preview or proof of audience response. Keep the approved images, supporting text and intended order together in the delivery record.
For recurring work, note the next review or publication task in the content calendar generator. Assign an owner to verify that the right revision reaches the right destination. The compressor does not send images into SMTasker, connect a social account or perform native uploading. Any later supported account routine is separate from this browser-based preparation, and a selected platform is not permission or capability to publish there automatically.
Close the job with a clear acceptance record: which outputs fit the brief, which miss a requested budget, and which need a different format or source edit. Retain originals and the useful review figures, then remove unapproved copies from the handoff folder. Explore the free tools directory for a distinct next task. The practical outcome is an understandable set of reviewed derivatives, not a promise of guaranteed savings, better reach or unchanged visual quality.
Match the review to the image
Platform and export guides
Use the destination-specific examples or work through a byte budget and format choice.
Instagram Images
Instagram image compression is a delivery decision, not a reason to make every photo equally small. Start with the details that explain your subject, then reduce file weight while checking those details across the complete set. A ceramics campaign shows why matching settings and matching visual quality are different jobs.
Read the instagram images guideTikTok Photos
A photo sequence works only when each step remains understandable. For instructional TikTok photos, a blurred quantity or missing word matters more than a small difference in background texture. Review compression around the action and its label, while keeping the uncompressed references that let you check both.
Read the tiktok photos guideYouTube Thumbnails
A thumbnail delivery needs more than a small file. The editor needs to know which concept was approved, which details survived compression, and which image should actually be applied to the video. Use a science-video example to separate those decisions and keep the review record attached to the right asset.
Read the youtube thumbnails guideFacebook Event Images
A neighborhood event produces more than photographs. There may be a poster, a timetable, a sponsor graphic, and a folder of moments worth keeping. Compressing that mixed collection well starts with deciding what each image must preserve, not choosing one aggressive setting for everything.
Read the facebook event images guideLinkedIn Charts and Screenshots
A business image can look polished while hiding the detail that makes its claim meaningful. For a chart, that might be a unit or sample note. For a screenshot, it might be a selected filter. Prepare smaller delivery files only after deciding which evidence a reader needs to inspect.
Read the linkedin charts and screenshots guideThreads Garden Updates
A conversation photo does not have to explain an entire project. It needs to show the detail your words are talking about. For a community garden, that could be a new path, a seed label, or a small change since the last update. Compress for that purpose while keeping the original available for the next question.
Read the threads garden updates guideX (Twitter) Images
An image of a service update succeeds when someone can distinguish the route, direction, and affected time. A smaller download is useful only if those details survive. Review screenshot text and news graphics by the information they carry, not by the largest percentage saving in a results table.
Read the x (twitter) images guideSnapchat Still Images
A pop-up event image often has two jobs: make the event inviting and help someone find it. Preserve the sign, entrance, date, and time before chasing a smaller file. This workflow is for still photographs and designed still Story assets, not video, animation, or a filter effect.
Read the snapchat still images guideReddit Image Detail
A repair photograph is useful when readers can see the feature you are discussing. Smaller files help with handling, but an attractive overview cannot replace a clear joint close-up. Prepare a woodworking repair log by preserving context, comparable views, and the specific marks that support your explanation.
Read the reddit image detail guideCompress Images to a Target Size
A target file size is a delivery condition, not a promise that every image can meet it acceptably. Start by confirming the byte allowance and the detail the recipient needs. Then use sampled compression results to decide what can be delivered, what needs another treatment, and what requires a conversation about the brief.
Read the compress images to a target size guideJPG, PNG and WebP Compression
A photograph, a transparent brand mark and an assembly diagram do not ask the same thing of an image format. Decide what each asset must preserve before comparing its bytes. This guide uses a mixed brand library to show why the smallest file can be unsuitable, and why a larger result can still be the appropriate delivery copy.
Read the jpg, png and webp compression guide