This page looks at the counts of outstanding tag aliases,
tag implications, and bulk update requests on e621, and how those
have changed from 2023 through 2026.
Update, 2026-08-15
The original version of this experiment was posted in October
2023, and then updated in July 2024. For the 2024 version, click
here. This experiment has
been updated with new data through mid-August, 2026.
Summary
As of mid-August, 2026, e621's BUR system seems to be mostly abandoned.
As of mid-August, 2026, the alias and implication system is maintained somewhat, but at least the pending aliases are approaching a level that triggered mass rejections in early 2024.
For 2026 so far, the alias backlog is growing by about 32 aliases per month, and the implication backlog is growing by about 29 implications per month.
Based on a short sample size, from mid-June to mid-August 2026, the BUR backlog is growing by about 139 BURs per month.
As of mid-August, 2026, the oldest pending alias is about
4.4 years old, the oldest pending implication is about 4.6
years old, and the oldest pending BUR is about 3.7 years old.
Table of contents
Graph
Methodology
Discussion
Background
Future prospects
Conclusions
Graph
Important: This graph doesn't automatically update every
day. It was created one time, in mid-August 2026.
Methodology
It has always been possible to determine the number of pending aliases and implications from the database export files that e621 provides. Furbitron does not normally use these files, so it does not regularly fetch them. Furbitron does have a few copies of the export files from various dates, and for these graphs, more were downloaded from archive.org's periodic backups of e621's database export page.
This graph uses a vertical tick to show the date of the export file, along with a dashed line between ticks. This includes data from December 2022 to September 2023, and from March 2025 until mid-August 2026.
From September 2023 until February 2025, Furbitron was able to directly query e621 for the number of pending aliases, implications, and BURs. This data is shown here as solid lines during that time period. e621 blocked Furbitron's ability to make this query starting in February 2025.
In June 2026, e621 added a bulk update request file to the database export, which can be used to determine the number of pending BURs. Furbitron downloaded these files, both live and from archive.org. The data from these files is shown as vertical ticks with a dashed line between them, from June 2026 to mid-August 2026.
Each alias, implication, or BUR has a serial ID number in
its file. The age of the oldest pending item can be determined
by looking for the "pending" item with the lowest number.
Discussion
Approval of tag aliases, implications, and BURs on e621 is not instant or automatic. There is usually at least a few days' worth of discussion and voting before approval is granted. The approval has to be manually done by a member of e621 staff.
The time for approval can also vary widely. For example, Furbitron is aware of some aliases that were proposed in 2020 and 2021 that took anywhere from one week, to six months, to twenty months to be approved.
Due to this variability, the backlog of pending aliases, implications, and BURs has tended to grow over time.
In July 2022, one of the e621 staff bumped a forum thread that invited users to name pending alias and implication requests that could probably be approved quickly by the staff. Several users did so, and several of the pending requests were approved. The same member of staff bumped the thread again in December 2022, which resulted in some additional approvals of old requests, through about March 2023.
The backlog still continued to grow. In response, the lead e621 staff member made a forum post in mid-May 2023, advising that the staff planned to reject all pending requests from 2016 on the first of June, 2023. That post also asked users to bring up any pending requests from 2016 that they thought had merit. A subsequent post in the thread also claimed that the plan was to reject pending requests from 2017 on the first of July, and to continue rejecting old pending requests at the "one year per month" rate.
Several users brought up requests that were still pending from 2016, and some of those were approved. On the first of June, 2023, the remaining pending requests from 2016 were rejected.
On the second of June, the lead staff member made a forum post announcing that the staff planned to reject all pending requests from 2017 on the first of July, 2023. They again called on users to bring up pending requests from 2017 that they thought had merit, and some users did so. However, the first of July came and went without any further action on the pending requests from 2017.
After that, approvals of pending tag aliases, implications, and BURs seemed to come to a screeching halt for the rest of 2023 and into early 2024.
On January 8, 2024, the lead staff member made a forum post announcing that all pending aliases and implications from 2021 and before had been rejected. This post did not mention pending BURs, but Furbitron's monitoring showed that no BURs were included in this mass rejection.
Starting about March 11, 2024, and continuing for a week, there was an effort to either approve or reject a number of aliases. This was not a mass rejection - the staff appeared to be reviewing individual aliases at this time.
Starting about March 18, 2024, and continuing for about 11 days, there was a similar effort directed at BURs.
In late October, 2024, there was another effort to either approve or reject a number of aliases and implications. This can be clearly seen by the large drop in the number of pending aliases at this time.
Since that time, Furbitron has had less visibility into the alias, implication, and BUR activity. The graph does show that the number of aliases and implications has fluctuated up and down.
In general, the number of pending aliases has increased to near 1,500, which is the same level they were at when the mass rejection was done in January 2024. The number of pending implications has risen to a bit over 900.
At the end of Furbitron's daily monitoring in February, 2025,
there were about 2,450 pending BURs. Since then, this count has
soared to nearly 4,700 in mid-August 2026. This is the basis for
Furbitron's claim that the BUR system has been abandoned.
Background
This section provides some background information on e621's alias, implication, and bulk update request (AIBUR) features.
Like most other furry art sites, e621 allows each submission to have a number of tags - key words that describe the contents of the image.
Unlike some other furry art sites, e621's tag system is very extensive, and users of the site can easily add, delete, and modify almost all of the tags on almost every submission.
To assist in standardizing the tags, which makes searching by tags work better, e621 supports the ideas of "tag aliases" and "tag implications".
An alias replaces one tag with a more-preferred tag. For example, if a user tries to tag a submission with "bunny", the alias system automatically changes that tag to "rabbit". Aliases are also used when an artist has changed names; the alias system will automatically change the old artist tag to the new one.
An implication adds additional tags that are related to the tag a user has applied. For example, if a user tags a submission with "rabbit", the implication system automatically adds the tags "leporid", "lagomorph", and "mammal".
New aliases and implications can be proposed by any registered user of e621. There is a dedicated area on the e621 forum for these proposals, where they are discussed and voted on by other users.
Sometimes the conclusion is that the proposed alias or implication is not useful, so the proposal is rejected. Sometimes the proposal is modified into something more useful. Once other users generally agree that the proposal would be useful, a member of the e621 staff approves the proposal, which makes it apply to all tagging activity on the site from that point forward.
Aliases and implications can normally only be proposed for one tag at a time. In some cases, it is convenient to group several related aliases or implications together, for discussion as a single group. This can be done with a "bulk update request" or "BUR". BURs are proposed and discussed on the e621 forums in the same way that single tag aliases or implications are.
For example, when a new generation of Pokémon is introduced, e621's custom is to have the name of each new Pokémon imply a tag like "generation_14_pokemon". Rather than make about 100 separate implication requests for this, a BUR allows all of the proposed implications to be listed in a single place, discussed, and approved all at one time.
(BURs also have some additional capabilities that simple
aliases and implications don't have, but that is out of scope
for this page.)
Future prospects
As of late July, 2026, e621 has introduced an "upload karma" system. This allows prolific uploaders to bypass the requirement for staff approval of a newly-uploaded image. (For reference, in early 2023, the upload rate to e621 was about 1,900 images a day. In mid-August 2026, it's up to about 2,500 images a day.) This doesn't directly affect the AIBURs, but it may allow some staff to spend more time on the AIBUR backlog, rather than the image upload queue.
There has been a little discussion in the forums about having
an "undo" functionality for AIBURs available to staff. Aliases
and implications only work on one tag at a time, so they are
fairly easy to reverse if there is a problem. BURs can work on
potentially dozens or hundreds of tags at once, so reversing
one is more involved. If an "undo" function is available, staff
can have reassurance that serious mistakes can be reverted.
Conclusions
As of mid-August, 2026, e621's BUR system seems to be mostly abandoned.
As of mid-August, 2026, the alias and implication system is maintained somewhat, but at least the pending aliases are approaching a level that triggered mass rejections in early 2024.
For 2026 so far, the alias backlog is growing by about 32 aliases per month, and the implication backlog is growing by about 29 implications per month.
Based on a short sample size, from mid-June to mid-August 2026, the BUR backlog is growing by about 139 BURs per month.
As of mid-August, 2026, the oldest pending alias is about 4.4 years old, the oldest pending implication is about 4.6 years old, and the oldest pending BUR is about 3.7 years old.