Resonators 
are the central item of Ingress, enabling Agents to capture Portals and use them to form Control Fields Δ.
Deploying a Resonator on a Portal captures it, aligns it to a faction, determines its level, affects the amount of Exotic Matter (XM) it drops, enables linking and fielding, earns Access Points (AP), and causes the Agent to receive notifications when the Portal is attacked.
Up to eight Resonators can be deployed on a single Portal. Higher-level Resonators have deployment restrictions that limit how many a single Agent can place. Because Links require both Portals to contain eight Resonators and their length is primarily determined by the Portal's level, Agents must carry a variety of Resonators to create longer Links and larger Control Fields Δ.
Until Resonators are deployed on a Portal they have no alignment which is indicated by the XM-coloured edging (see pictures in the infobox). Only once the are deployed they align themselves with the Agent's faction and as indicated by the edging changing from XM-coloured to either Enlightened 
green or Resistance 
blue and subsequently also alight their assosiated Portal. After they have aligned themselves to a faction this alignment can only be changed via the use of JARVIS Viruses 
or ADA Refactors 
(Flip Cards).
Resonators are the most common items received from hacking. Community studies estimate that approximately 1.5 Resonators are received from every item roll.
Deployment and Upgrading[]
| Resonator level |
Coloration [* pre Ingress Prime] |
Agent Limit |
XM Provided to Portal |
Recycle Value |
|---|---|---|---|---|
| L1 |  |  *
|
8 | 1 000 XM | 20 XM |
| L2 |  |  *
|
4 | 1 500 XM | 40 XM |
| L3 |  |  *
|
4 | 2 000 XM | 60 XM |
| L4 |  |  *
|
4 | 2 500 XM | 80 XM |
| L5 |  |  *
|
2 | 3 000 XM | 100 XM |
| L6 |  |  *
|
2 | 4 000 XM | 120 XM |
| L7 |  |  *
|
1 | 5 000 XM | 140 XM |
| L8 |  |  *
|
1 | 6 000 XM | 160 XM |
An Agent can deploy a Resonator on a Portal if all of these conditions are met:
- The Agent's level is equal to or greater than the Resonator's
level. - The number of Resonators (of the specific level) on the Portal owned by the Agent* is below the Agent limit.
- The Portal has an open Resonator slot or the Portal already contains a Resonator of lower level than the new Resonator .
* If a Flip Card is used to flip a Portal to the Agent's faction the Agent will automatically gain ownership of all Resonators and Mods on the Portal regardless of the limits.
Deploying a Resonator places it onto the Scanner map in one of the eight cardinal and ordinal directions. The Resonator will be placed at the same distance from the Portal as the Agent deployed it.
Agents can simply select a Portal, tap on the 
'Deploy'-button, select the Resonator from the selector menu and press the 'Deploy'-button at the top to place a Resonator at the free slot closest to themselves. Alternatively the Agent can also manually select one of the free slots to deploy into or, when all slot are already occupied, one of the slots they can upgrade. The northernmost slot is indicated by a red arrow.
To upgrade a Resonator , all eight slots must be filled and the target Resonator must be manually selected. The Scanner will attempt to select the next-highest level Resonator from the Agent's inventory, but any Resonator of a higher level than the target can be used to upgrade.
Effect on Portal level[]
A Portal's level is the average of all eight Resonator slots, rounded down. If there is no Resonator in a slot, it is counted as zero. Although an average can land below zero, the Portal's level will always be at least Level 1.
- A Portal with four L8 Resonators will be Level 4, since there are four slots counted as zero.
- A Portal with seven L8 Resonators and only one L7 will be Level 7, since the average is rounded down.
XM and Combat[]
In the Ingress lore, Resonators contain structured Exotic Matter (XM) that power the attached Portal. This XM is depleted by enemy attacks and decays by 15% of the Resonator's capacity every 24 hours.
Attacking a Resonator with an XMP Burster 
or Ultra Strike 
reduces the amount of XM it contains. The weapon's base damage, minus mitigation and range penalties and multiplied by the attack's charge bonus, is subtracted from the affected Resonators . The Portal will occasionally counterattack and drain an amount of XM from the attacker proportional to its level.
When a Resonator's XM is completely depleted, it is destroyed. When the number of existing Resonators on a Portal drops below three Resonators , all Links attached to the Portal will be broken.
Agents can replenish a Resonator's XM by recharging it. This can be performed locally by standing within range of the Portal, or remotely through the corresponding Portal Key 
. Recharging is one-to-one - each XM going into a Resonator must come out of the Agent's XM tank.
Every 20 minutes, a Portal emits 20% of its total XM in the 40m radius surrounding it. This loose XM can be picked up by Agents of either faction.
A maxed-out Level 8 Portal contains 48 000 XM.
Strategy[]
The creation of high-level Portals requires multiple Agents. Agents must seek out and coordinate with allies nearby, or enemies will destroy low-level Portals before allies can increase their level.
Because the level of a Portal determines the average level of Resonators it will drop, Agents must hack a diverse set of Portals to obtain a variety of differently-leveled Resonators . A popular trick used by Agents who enjoy building Control Fields Δ is to deploy 1x L8, 1x L7, 2x L6, and 1x L5 Resonator 
on a Portal, then Glyph Hack the new L4 Portal to obtain the L5 and 2x L4 Resonators 
required to finish it.
This also implies that if an Agent is cut off from L8 Portals for a significant length of time, his or her ability to 'bump' Portals to L7 or L8 with a L8 Resonator 
will be constrained. The savvy Agent carefully considers his or her future access to high-level Portals when determining how he or she will deploy and stockpile L8 Resonators .
Many Agents prefer to deploy 1x L8, 1x L7, and 2x L6 Resonators 
on unclaimed Portals. This enables another friendly Agent to add the same configuration and bump it to Level 6, or simply Glyph Hack it as-is to obtain enough Resonators to complete and Link it.
The 625 AP reward for capturing a Portal is substantial, and Agents often deploy a single Resonator on an unclaimed Portal to earn it. You get 375 AP for deploying the last Resonator . If the Agent is unsure if the Portal will be upgraded others or used to complete a Control Field Δ, he or she will intentionally avoid filling the other seven slots to conserve resources. Agents may also do this to obtain the Liberator-Medal. Alternately, he or she may fill it out with low-level Resonators if he or she believes friendly Agents will soon Link to it.
For maximum AP gain or to obtain the Builder-Medal, two Agents can alternate upgrading each other's Resonators . The first Agent deploys eight L1's. The second upgrades four of them with L2's. The first upgrades the L2's to L3's. The second Agent can now upgrade the remaining L1's to L2's and continues the cycle.
